Class OffsetDateTime

java.lang.Object
java.time.OffsetDateTime
All Implemented Interfaces:
Serializable, Comparable<OffsetDateTime>, Temporal, TemporalAccessor, TemporalAdjuster
public final class OffsetDateTime extends Object implements Temporal, TemporalAdjuster, Comparable<OffsetDateTime>, Serializable
A date-time with an offset from UTC/Greenwich in the ISO-8601 calendar system, such as 2007-12-03T10:15:30+01:00.

OffsetDateTime is an immutable representation of a date-time with an offset. This class stores all date and time fields, to a precision of nanoseconds, as well as the offset from UTC/Greenwich. For example, the value "2nd October 2007 at 13:45:30.123456789 +02:00" can be stored in an OffsetDateTime.

OffsetDateTime, ZonedDateTime and Instant all store an instant on the time-line to nanosecond precision. Instant is the simplest, simply representing the instant. OffsetDateTime adds to the instant the offset from UTC/Greenwich, which allows the local date-time to be obtained. ZonedDateTime adds full time-zone rules.

It is intended that ZonedDateTime or Instant is used to model data in simpler applications. This class may be used when modeling date-time concepts in more detail, or when communicating to a database or in a network protocol.

This is a value-based class; programmers should treat instances that are equal as interchangeable and should not use instances for synchronization, or unpredictable behavior may occur. For example, in a future release, synchronization may fail. The equals method should be used for comparisons.

Implementation Requirements:
This class is immutable and thread-safe.
Since:
1.8
See Also:

  • Field Details

    • MIN

      public static final OffsetDateTime MIN
      The minimum supported OffsetDateTime, '-999999999-01-01T00:00:00+18:00'. This is the local date-time of midnight at the start of the minimum date in the maximum offset (larger offsets are earlier on the time-line). This combines LocalDateTime.MIN and ZoneOffset.MAX. This could be used by an application as a "far past" date-time.

    • MAX

      public static final OffsetDateTime MAX
      The maximum supported OffsetDateTime, '+999999999-12-31T23:59:59.999999999-18:00'. This is the local date-time just before midnight at the end of the maximum date in the minimum offset (larger negative offsets are later on the time-line). This combines LocalDateTime.MAX and ZoneOffset.MIN. This could be used by an application as a "far future" date-time.

  • Method Details

    • timeLineOrder

      public static Comparator<OffsetDateTime> timeLineOrder()
      Gets a comparator that compares two OffsetDateTime instances based solely on the instant.

      This method differs from the comparison in compareTo(java.time.OffsetDateTime) in that it only compares the underlying instant.

      Returns:
      a comparator that compares in time-line order
      See Also:

    • now

      public static OffsetDateTime now()
      Obtains the current date-time from the system clock in the default time-zone.

      This will query the system clock in the default time-zone to obtain the current date-time. The offset will be calculated from the time-zone in the clock.

      Using this method will prevent the ability to use an alternate clock for testing because the clock is hard-coded.

      Returns:
      the current date-time using the system clock, not null

    • now

      public static OffsetDateTime now(ZoneId zone)
      Obtains the current date-time from the system clock in the specified time-zone.

      This will query the system clock to obtain the current date-time. Specifying the time-zone avoids dependence on the default time-zone. The offset will be calculated from the specified time-zone.

      Using this method will prevent the ability to use an alternate clock for testing because the clock is hard-coded.

      Parameters:
      zone - the zone ID to use, not null
      Returns:
      the current date-time using the system clock, not null

    • now

      public static OffsetDateTime now(Clock clock)
      Obtains the current date-time from the specified clock.

      This will query the specified clock to obtain the current date-time. The offset will be calculated from the time-zone in the clock.

      Using this method allows the use of an alternate clock for testing. The alternate clock may be introduced using dependency injection.

      Parameters:
      clock - the clock to use, not null
      Returns:
      the current date-time, not null

    • of

      public static OffsetDateTime of(LocalDate date, LocalTime time, ZoneOffset offset)
      Obtains an instance of OffsetDateTime from a date, time and offset.

      This creates an offset date-time with the specified local date, time and offset.

      Parameters:
      date - the local date, not null
      time - the local time, not null
      offset - the zone offset, not null
      Returns:
      the offset date-time, not null

    • of

      public static OffsetDateTime of(LocalDateTime dateTime, ZoneOffset offset)
      Obtains an instance of OffsetDateTime from a date-time and offset.

      This creates an offset date-time with the specified local date-time and offset.

      Parameters:
      dateTime - the local date-time, not null
      offset - the zone offset, not null
      Returns:
      the offset date-time, not null

    • of

      public static OffsetDateTime of(int year, int month, int dayOfMonth, int hour, int minute, int second, int nanoOfSecond, ZoneOffset offset)
      Obtains an instance of OffsetDateTime from a year, month, day, hour, minute, second, nanosecond and offset.

      This creates an offset date-time with the seven specified fields.

      This method exists primarily for writing test cases. Non test-code will typically use other methods to create an offset time. LocalDateTime has five additional convenience variants of the equivalent factory method taking fewer arguments. They are not provided here to reduce the footprint of the API.

      Parameters:
      year - the year to represent, from MIN_YEAR to MAX_YEAR
      month - the month-of-year to represent, from 1 (January) to 12 (December)
      dayOfMonth - the day-of-month to represent, from 1 to 31
      hour - the hour-of-day to represent, from 0 to 23
      minute - the minute-of-hour to represent, from 0 to 59
      second - the second-of-minute to represent, from 0 to 59
      nanoOfSecond - the nano-of-second to represent, from 0 to 999,999,999
      offset - the zone offset, not null
      Returns:
      the offset date-time, not null
      Throws:
      DateTimeException - if the value of any field is out of range, or if the day-of-month is invalid for the month-year

    • ofInstant

      public static OffsetDateTime ofInstant(Instant instant, ZoneId zone)
      Obtains an instance of OffsetDateTime from an Instant and zone ID.

      This creates an offset date-time with the same instant as that specified. Finding the offset from UTC/Greenwich is simple as there is only one valid offset for each instant.

      Parameters:
      instant - the instant to create the date-time from, not null
      zone - the time-zone, which may be an offset, not null
      Returns:
      the offset date-time, not null
      Throws:
      DateTimeException - if the result exceeds the supported range

    • from

      public static OffsetDateTime from(TemporalAccessor temporal)
      Obtains an instance of OffsetDateTime from a temporal object.

      This obtains an offset date-time based on the specified temporal. A TemporalAccessor represents an arbitrary set of date and time information, which this factory converts to an instance of OffsetDateTime.

      The conversion will first obtain a ZoneOffset from the temporal object. It will then try to obtain a LocalDateTime, falling back to an Instant if necessary. The result will be the combination of ZoneOffset with either with LocalDateTime or Instant. Implementations are permitted to perform optimizations such as accessing those fields that are equivalent to the relevant objects.

      This method matches the signature of the functional interface TemporalQuery allowing it to be used as a query via method reference, OffsetDateTime::from.

      Parameters:
      temporal - the temporal object to convert, not null
      Returns:
      the offset date-time, not null
      Throws:
      DateTimeException - if unable to convert to an OffsetDateTime

    • parse

      public static OffsetDateTime parse(CharSequence text)
      Obtains an instance of OffsetDateTime from a text string such as 2007-12-03T10:15:30+01:00.

      The string must represent a valid date-time and is parsed using DateTimeFormatter.ISO_OFFSET_DATE_TIME.

      Parameters:
      text - the text to parse such as "2007-12-03T10:15:30+01:00", not null
      Returns:
      the parsed offset date-time, not null
      Throws:
      DateTimeParseException - if the text cannot be parsed

    • parse

      public static OffsetDateTime parse(CharSequence text, DateTimeFormatter formatter)
      Obtains an instance of OffsetDateTime from a text string using a specific formatter.

      The text is parsed using the formatter, returning a date-time.

      Parameters:
      text - the text to parse, not null
      formatter - the formatter to use, not null
      Returns:
      the parsed offset date-time, not null
      Throws:
      DateTimeParseException - if the text cannot be parsed

    • isSupported

      public boolean isSupported(TemporalField field)
      Checks if the specified field is supported.

      This checks if this date-time can be queried for the specified field. If false, then calling the range, get and with(TemporalField, long) methods will throw an exception.

      If the field is a ChronoField then the query is implemented here. The supported fields are:

      • NANO_OF_SECOND
      • NANO_OF_DAY
      • MICRO_OF_SECOND
      • MICRO_OF_DAY
      • MILLI_OF_SECOND
      • MILLI_OF_DAY
      • SECOND_OF_MINUTE
      • SECOND_OF_DAY
      • MINUTE_OF_HOUR
      • MINUTE_OF_DAY
      • HOUR_OF_AMPM
      • CLOCK_HOUR_OF_AMPM
      • HOUR_OF_DAY
      • CLOCK_HOUR_OF_DAY
      • AMPM_OF_DAY
      • DAY_OF_WEEK
      • ALIGNED_DAY_OF_WEEK_IN_MONTH
      • ALIGNED_DAY_OF_WEEK_IN_YEAR
      • DAY_OF_MONTH
      • DAY_OF_YEAR
      • EPOCH_DAY
      • ALIGNED_WEEK_OF_MONTH
      • ALIGNED_WEEK_OF_YEAR
      • MONTH_OF_YEAR
      • PROLEPTIC_MONTH
      • YEAR_OF_ERA
      • YEAR
      • ERA
      • INSTANT_SECONDS
      • OFFSET_SECONDS
      All other ChronoField instances will return false.

      If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.isSupportedBy(TemporalAccessor) passing this as the argument. Whether the field is supported is determined by the field.

      Specified by:
      isSupported in interface TemporalAccessor
      Parameters:
      field - the field to check, null returns false
      Returns:
      true if the field is supported on this date-time, false if not

    • isSupported

      public boolean isSupported(TemporalUnit unit)
      Checks if the specified unit is supported.

      This checks if the specified unit can be added to, or subtracted from, this date-time. If false, then calling the plus(long, TemporalUnit) and minus methods will throw an exception.

      If the unit is a ChronoUnit then the query is implemented here. The supported units are:

      • NANOS
      • MICROS
      • MILLIS
      • SECONDS
      • MINUTES
      • HOURS
      • HALF_DAYS
      • DAYS
      • WEEKS
      • MONTHS
      • YEARS
      • DECADES
      • CENTURIES
      • MILLENNIA
      • ERAS
      All other ChronoUnit instances will return false.

      If the unit is not a ChronoUnit, then the result of this method is obtained by invoking TemporalUnit.isSupportedBy(Temporal) passing this as the argument. Whether the unit is supported is determined by the unit.

      Specified by:
      isSupported in interface Temporal
      Parameters:
      unit - the unit to check, null returns false
      Returns:
      true if the unit can be added/subtracted, false if not

    • range

      public ValueRange range(TemporalField field)
      Gets the range of valid values for the specified field.

      The range object expresses the minimum and maximum valid values for a field. This date-time is used to enhance the accuracy of the returned range. If it is not possible to return the range, because the field is not supported or for some other reason, an exception is thrown.

      If the field is a ChronoField then the query is implemented here. The supported fields will return appropriate range instances. All other ChronoField instances will throw an UnsupportedTemporalTypeException.

      If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.rangeRefinedBy(TemporalAccessor) passing this as the argument. Whether the range can be obtained is determined by the field.

      Specified by:
      range in interface TemporalAccessor
      Parameters:
      field - the field to query the range for, not null
      Returns:
      the range of valid values for the field, not null
      Throws:
      DateTimeException - if the range for the field cannot be obtained
      UnsupportedTemporalTypeException - if the field is not supported

    • get

      public int get(TemporalField field)
      Gets the value of the specified field from this date-time as an int.

      This queries this date-time for the value of the specified field. The returned value will always be within the valid range of values for the field. If it is not possible to return the value, because the field is not supported or for some other reason, an exception is thrown.

      If the field is a ChronoField then the query is implemented here. The supported fields will return valid values based on this date-time, except NANO_OF_DAY, MICRO_OF_DAY, EPOCH_DAY, PROLEPTIC_MONTH and INSTANT_SECONDS which are too large to fit in an int and throw an UnsupportedTemporalTypeException. All other ChronoField instances will throw an UnsupportedTemporalTypeException.

      If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.getFrom(TemporalAccessor) passing this as the argument. Whether the value can be obtained, and what the value represents, is determined by the field.

      Specified by:
      get in interface TemporalAccessor
      Parameters:
      field - the field to get, not null
      Returns:
      the value for the field
      Throws:
      DateTimeException - if a value for the field cannot be obtained or the value is outside the range of valid values for the field
      UnsupportedTemporalTypeException - if the field is not supported or the range of values exceeds an int
      ArithmeticException - if numeric overflow occurs

    • getLong

      public long getLong(TemporalField field)
      Gets the value of the specified field from this date-time as a long.

      This queries this date-time for the value of the specified field. If it is not possible to return the value, because the field is not supported or for some other reason, an exception is thrown.

      If the field is a ChronoField then the query is implemented here. The supported fields will return valid values based on this date-time. All other ChronoField instances will throw an UnsupportedTemporalTypeException.

      If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.getFrom(TemporalAccessor) passing this as the argument. Whether the value can be obtained, and what the value represents, is determined by the field.

      Specified by:
      getLong in interface TemporalAccessor
      Parameters:
      field - the field to get, not null
      Returns:
      the value for the field
      Throws:
      DateTimeException - if a value for the field cannot be obtained
      UnsupportedTemporalTypeException - if the field is not supported
      ArithmeticException - if numeric overflow occurs

    • getOffset

      public ZoneOffset getOffset()
      Gets the zone offset, such as '+01:00'.

      This is the offset of the local date-time from UTC/Greenwich.

      Returns:
      the zone offset, not null

    • withOffsetSameLocal

      public OffsetDateTime withOffsetSameLocal(ZoneOffset offset)
      Returns a copy of this OffsetDateTime with the specified offset ensuring that the result has the same local date-time.

      This method returns an object with the same LocalDateTime and the specified ZoneOffset. No calculation is needed or performed. For example, if this time represents 2007-12-03T10:30+02:00 and the offset specified is +03:00, then this method will return 2007-12-03T10:30+03:00.

      To take into account the difference between the offsets, and adjust the time fields, use withOffsetSameInstant(java.time.ZoneOffset).

      This instance is immutable and unaffected by this method call.

      Parameters:
      offset - the zone offset to change to, not null
      Returns:
      an OffsetDateTime based on this date-time with the requested offset, not null

    • withOffsetSameInstant

      public OffsetDateTime withOffsetSameInstant(ZoneOffset offset)
      Returns a copy of this OffsetDateTime with the specified offset ensuring that the result is at the same instant.

      This method returns an object with the specified ZoneOffset and a LocalDateTime adjusted by the difference between the two offsets. This will result in the old and new objects representing the same instant. This is useful for finding the local time in a different offset. For example, if this time represents 2007-12-03T10:30+02:00 and the offset specified is +03:00, then this method will return 2007-12-03T11:30+03:00.

      To change the offset without adjusting the local time use withOffsetSameLocal(java.time.ZoneOffset).

      This instance is immutable and unaffected by this method call.

      Parameters:
      offset - the zone offset to change to, not null
      Returns:
      an OffsetDateTime based on this date-time with the requested offset, not null
      Throws:
      DateTimeException - if the result exceeds the supported date range

    • toLocalDateTime

      public LocalDateTime toLocalDateTime()
      Gets the LocalDateTime part of this date-time.

      This returns a LocalDateTime with the same year, month, day and time as this date-time.

      Returns:
      the local date-time part of this date-time, not null

    • toLocalDate

      public LocalDate toLocalDate()
      Gets the LocalDate part of this date-time.

      This returns a LocalDate with the same year, month and day as this date-time.

      Returns:
      the date part of this date-time, not null

    • getYear

      public int getYear()
      Gets the year field.

      This method returns the primitive int value for the year.

      The year returned by this method is proleptic as per get(YEAR). To obtain the year-of-era, use get(YEAR_OF_ERA).

      Returns:
      the year, from MIN_YEAR to MAX_YEAR

    • getMonthValue

      public int getMonthValue()
      Gets the month-of-year field from 1 to 12.

      This method returns the month as an int from 1 to 12. Application code is frequently clearer if the enum Month is used by calling getMonth().

      Returns:
      the month-of-year, from 1 to 12
      See Also:

    • getMonth

      public Month getMonth()
      Gets the month-of-year field using the Month enum.

      This method returns the enum Month for the month. This avoids confusion as to what int values mean. If you need access to the primitive int value then the enum provides the int value.

      Returns:
      the month-of-year, not null
      See Also:

    • getDayOfMonth

      public int getDayOfMonth()
      Gets the day-of-month field.

      This method returns the primitive int value for the day-of-month.

      Returns:
      the day-of-month, from 1 to 31

    • getDayOfYear

      public int getDayOfYear()
      Gets the day-of-year field.

      This method returns the primitive int value for the day-of-year.

      Returns:
      the day-of-year, from 1 to 365, or 366 in a leap year

    • getDayOfWeek

      public DayOfWeek getDayOfWeek()
      Gets the day-of-week field, which is an enum DayOfWeek.

      This method returns the enum DayOfWeek for the day-of-week. This avoids confusion as to what int values mean. If you need access to the primitive int value then the enum provides the int value.

      Additional information can be obtained from the DayOfWeek. This includes textual names of the values.

      Returns:
      the day-of-week, not null

    • toLocalTime

      public LocalTime toLocalTime()
      Gets the LocalTime part of this date-time.

      This returns a LocalTime with the same hour, minute, second and nanosecond as this date-time.

      Returns:
      the time part of this date-time, not null

    • getHour

      public int getHour()
      Gets the hour-of-day field.
      Returns:
      the hour-of-day, from 0 to 23

    • getMinute

      public int getMinute()
      Gets the minute-of-hour field.
      Returns:
      the minute-of-hour, from 0 to 59

    • getSecond

      public int getSecond()
      Gets the second-of-minute field.
      Returns:
      the second-of-minute, from 0 to 59

    • getNano

      public int getNano()
      Gets the nano-of-second field.
      Returns:
      the nano-of-second, from 0 to 999,999,999

    • with

      public OffsetDateTime with(TemporalAdjuster adjuster)
      Returns an adjusted copy of this date-time.

      This returns an OffsetDateTime, based on this one, with the date-time adjusted. The adjustment takes place using the specified adjuster strategy object. Read the documentation of the adjuster to understand what adjustment will be made.

      A simple adjuster might simply set the one of the fields, such as the year field. A more complex adjuster might set the date to the last day of the month. A selection of common adjustments is provided in TemporalAdjusters. These include finding the "last day of the month" and "next Wednesday". Key date-time classes also implement the TemporalAdjuster interface, such as Month and MonthDay. The adjuster is responsible for handling special cases, such as the varying lengths of month and leap years.

      For example this code returns a date on the last day of July: 

        import static java.time.Month.*;
  import static java.time.temporal.TemporalAdjusters.*;

  result = offsetDateTime.with(JULY).with(lastDayOfMonth());

      The classes LocalDate, LocalTime and ZoneOffset implement TemporalAdjuster, thus this method can be used to change the date, time or offset: 

        result = offsetDateTime.with(date);
  result = offsetDateTime.with(time);
  result = offsetDateTime.with(offset);

      The result of this method is obtained by invoking the TemporalAdjuster.adjustInto(Temporal) method on the specified adjuster passing this as the argument.

      This instance is immutable and unaffected by this method call.

      Specified by:
      with in interface Temporal
      Parameters:
      adjuster - the adjuster to use, not null
      Returns:
      an OffsetDateTime based on this with the adjustment made, not null
      Throws:
      DateTimeException - if the adjustment cannot be made
      ArithmeticException - if numeric overflow occurs

    • with

      public OffsetDateTime with(TemporalField field, long newValue)
      Returns a copy of this date-time with the specified field set to a new value.

      This returns an OffsetDateTime, based on this one, with the value for the specified field changed. This can be used to change any supported field, such as the year, month or day-of-month. If it is not possible to set the value, because the field is not supported or for some other reason, an exception is thrown.

      In some cases, changing the specified field can cause the resulting date-time to become invalid, such as changing the month from 31st January to February would make the day-of-month invalid. In cases like this, the field is responsible for resolving the date. Typically it will choose the previous valid date, which would be the last valid day of February in this example.

      If the field is a ChronoField then the adjustment is implemented here.

      The INSTANT_SECONDS field will return a date-time with the specified instant. The offset and nano-of-second are unchanged. If the new instant value is outside the valid range then a DateTimeException will be thrown.

      The OFFSET_SECONDS field will return a date-time with the specified offset. The local date-time is unaltered. If the new offset value is outside the valid range then a DateTimeException will be thrown.

      The other supported fields will behave as per the matching method on LocalDateTime. In this case, the offset is not part of the calculation and will be unchanged.

      All other ChronoField instances will throw an UnsupportedTemporalTypeException.

      If the field is not a ChronoField, then the result of this method is obtained by invoking TemporalField.adjustInto(Temporal, long) passing this as the argument. In this case, the field determines whether and how to adjust the instant.

      This instance is immutable and unaffected by this method call.

      Specified by:
      with in interface Temporal
      Parameters:
      field - the field to set in the result, not null
      newValue - the new value of the field in the result
      Returns:
      an OffsetDateTime based on this with the specified field set, not null
      Throws:
      DateTimeException - if the field cannot be set
      UnsupportedTemporalTypeException - if the field is not supported
      ArithmeticException - if numeric overflow occurs

    • withYear

      public OffsetDateTime withYear(int year)
      Returns a copy of this OffsetDateTime with the year altered.

      The time and offset do not affect the calculation and will be the same in the result. If the day-of-month is invalid for the year, it will be changed to the last valid day of the month.

      This instance is immutable and unaffected by this method call.

      Parameters:
      year - the year to set in the result, from MIN_YEAR to MAX_YEAR
      Returns:
      an OffsetDateTime based on this date-time with the requested year, not null
      Throws:
      DateTimeException - if the year value is invalid

    • withMonth

      public OffsetDateTime withMonth(int month)
      Returns a copy of this OffsetDateTime with the month-of-year altered.

      The time and offset do not affect the calculation and will be the same in the result. If the day-of-month is invalid for the year, it will be changed to the last valid day of the month.

      This instance is immutable and unaffected by this method call.

      Parameters:
      month - the month-of-year to set in the result, from 1 (January) to 12 (December)
      Returns:
      an OffsetDateTime based on this date-time with the requested month, not null
      Throws:
      DateTimeException - if the month-of-year value is invalid

    • withDayOfMonth

      public OffsetDateTime withDayOfMonth(int dayOfMonth)
      Returns a copy of this OffsetDateTime with the day-of-month altered.

      If the resulting OffsetDateTime is invalid, an exception is thrown. The time and offset do not affect the calculation and will be the same in the result.

      This instance is immutable and unaffected by this method call.

      Parameters:
      dayOfMonth - the day-of-month to set in the result, from 1 to 28-31
      Returns:
      an OffsetDateTime based on this date-time with the requested day, not null
      Throws:
      DateTimeException - if the day-of-month value is invalid, or if the day-of-month is invalid for the month-year

    • withDayOfYear

      public OffsetDateTime withDayOfYear(int dayOfYear)
      Returns a copy of this OffsetDateTime with the day-of-year altered.

      The time and offset do not affect the calculation and will be the same in the result. If the resulting OffsetDateTime is invalid, an exception is thrown.

      This instance is immutable and unaffected by this method call.

      Parameters:
      dayOfYear - the day-of-year to set in the result, from 1 to 365-366
      Returns:
      an OffsetDateTime based on this date with the requested day, not null
      Throws:
      DateTimeException - if the day-of-year value is invalid, or if the day-of-year is invalid for the year

    • withHour

      public OffsetDateTime withHour(int hour)
      Returns a copy of this OffsetDateTime with the hour-of-day altered.

      The date and offset do not affect the calculation and will be the same in the result.

      This instance is immutable and unaffected by this method call.

      Parameters:
      hour - the hour-of-day to set in the result, from 0 to 23
      Returns:
      an OffsetDateTime based on this date-time with the requested hour, not null
      Throws:
      DateTimeException - if the hour value is invalid

    • withMinute

      public OffsetDateTime withMinute(int minute)
      Returns a copy of this OffsetDateTime with the minute-of-hour altered.

      The date and offset do not affect the calculation and will be the same in the result.

      This instance is immutable and unaffected by this method call.

      Parameters:
      minute - the minute-of-hour to set in the result, from 0 to 59
      Returns:
      an OffsetDateTime based on this date-time with the requested minute, not null
      Throws:
      DateTimeException - if the minute value is invalid

    • withSecond

      public OffsetDateTime withSecond(int second)
      Returns a copy of this OffsetDateTime with the second-of-minute altered.

      The date and offset do not affect the calculation and will be the same in the result.

      This instance is immutable and unaffected by this method call.

      Parameters:
      second - the second-of-minute to set in the result, from 0 to 59
      Returns:
      an OffsetDateTime based on this date-time with the requested second, not null
      Throws:
      DateTimeException - if the second value is invalid

    • withNano

      public OffsetDateTime withNano(int nanoOfSecond)
      Returns a copy of this OffsetDateTime with the nano-of-second altered.

      The date and offset do not affect the calculation and will be the same in the result.

      This instance is immutable and unaffected by this method call.

      Parameters:
      nanoOfSecond - the nano-of-second to set in the result, from 0 to 999,999,999
      Returns:
      an OffsetDateTime based on this date-time with the requested nanosecond, not null
      Throws:
      DateTimeException - if the nano value is invalid

    • truncatedTo

      public OffsetDateTime truncatedTo(TemporalUnit unit)
      Returns a copy of this OffsetDateTime with the time truncated.

      Truncation returns a copy of the original date-time with fields smaller than the specified unit set to zero. For example, truncating with the minutes unit will set the second-of-minute and nano-of-second field to zero.

      The unit must have a duration that divides into the length of a standard day without remainder. This includes all supplied time units on ChronoUnit and DAYS. Other units throw an exception.

      The offset does not affect the calculation and will be the same in the result.

      This instance is immutable and unaffected by this method call.

      Parameters:
      unit - the unit to truncate to, not null
      Returns:
      an OffsetDateTime based on this date-time with the time truncated, not null
      Throws:
      DateTimeException - if unable to truncate
      UnsupportedTemporalTypeException - if the unit is not supported

    • plus

      public OffsetDateTime plus(TemporalAmount amountToAdd)
      Returns a copy of this date-time with the specified amount added.

      This returns an OffsetDateTime, based on this one, with the specified amount added. The amount is typically Period or Duration but may be any other type implementing the TemporalAmount interface.

      The calculation is delegated to the amount object by calling TemporalAmount.addTo(Temporal). The amount implementation is free to implement the addition in any way it wishes, however it typically calls back to plus(long, TemporalUnit). Consult the documentation of the amount implementation to determine if it can be successfully added.

      This instance is immutable and unaffected by this method call.

      Specified by:
      plus in interface Temporal
      Parameters:
      amountToAdd - the amount to add, not null
      Returns:
      an OffsetDateTime based on this date-time with the addition made, not null
      Throws:
      DateTimeException - if the addition cannot be made
      ArithmeticException - if numeric overflow occurs

    • plus

      public OffsetDateTime plus(long amountToAdd, TemporalUnit unit)
      Returns a copy of this date-time with the specified amount added.

      This returns an OffsetDateTime, based on this one, with the amount in terms of the unit added. If it is not possible to add the amount, because the unit is not supported or for some other reason, an exception is thrown.

      If the field is a ChronoUnit then the addition is implemented by LocalDateTime.plus(long, TemporalUnit). The offset is not part of the calculation and will be unchanged in the result.

      If the field is not a ChronoUnit, then the result of this method is obtained by invoking TemporalUnit.addTo(Temporal, long) passing this as the argument. In this case, the unit determines whether and how to perform the addition.

      This instance is immutable and unaffected by this method call.

      Specified by:
      plus in interface Temporal
      Parameters:
      amountToAdd - the amount of the unit to add to the result, may be negative
      unit - the unit of the amount to add, not null
      Returns:
      an OffsetDateTime based on this date-time with the specified amount added, not null
      Throws:
      DateTimeException - if the addition cannot be made
      UnsupportedTemporalTypeException - if the unit is not supported
      ArithmeticException - if numeric overflow occurs

    • plusYears

      public OffsetDateTime plusYears(long years)
      Returns a copy of this OffsetDateTime with the specified number of years added.

      This method adds the specified amount to the years field in three steps:

      1. Add the input years to the year field
      2. Check if the resulting date would be invalid
      3. Adjust the day-of-month to the last valid day if necessary

      For example, 2008-02-29 (leap year) plus one year would result in the invalid date 2009-02-29 (standard year). Instead of returning an invalid result, the last valid day of the month, 2009-02-28, is selected instead.

      This instance is immutable and unaffected by this method call.

      Parameters:
      years - the years to add, may be negative
      Returns:
      an OffsetDateTime based on this date-time with the years added, not null
      Throws:
      DateTimeException - if the result exceeds the supported date range

    • plusMonths

      public OffsetDateTime plusMonths(long months)
      Returns a copy of this OffsetDateTime with the specified number of months added.

      This method adds the specified amount to the months field in three steps:

      1. Add the input months to the month-of-year field
      2. Check if the resulting date would be invalid
      3. Adjust the day-of-month to the last valid day if necessary

      For example, 2007-03-31 plus one month would result in the invalid date 2007-04-31. Instead of returning an invalid result, the last valid day of the month, 2007-04-30, is selected instead.

      This instance is immutable and unaffected by this method call.

      Parameters:
      months - the months to add, may be negative
      Returns:
      an OffsetDateTime based on this date-time with the months added, not null
      Throws:
      DateTimeException - if the result exceeds the supported date range

    • plusWeeks

      public OffsetDateTime plusWeeks(long weeks)
      Returns a copy of this OffsetDateTime with the specified number of weeks added.

      This method adds the specified amount in weeks to the days field incrementing the month and year fields as necessary to ensure the result remains valid. The result is only invalid if the maximum/minimum year is exceeded.

      For example, 2008-12-31 plus one week would result in 2009-01-07.

      This instance is immutable and unaffected by this method call.

      Parameters:
      weeks - the weeks to add, may be negative
      Returns:
      an OffsetDateTime based on this date-time with the weeks added, not null
      Throws:
      DateTimeException - if the result exceeds the supported date range

    • plusDays

      public OffsetDateTime plusDays(long days)
      Returns a copy of this OffsetDateTime with the specified number of days added.

      This method adds the specified amount to the days field incrementing the month and year fields as necessary to ensure the result remains valid. The result is only invalid if the maximum/minimum year is exceeded.

      For example, 2008-12-31 plus one day would result in 2009-01-01.

      This instance is immutable and unaffected by this method call.

      Parameters:
      days - the days to add, may be negative
      Returns:
      an OffsetDateTime based on this date-time with the days added, not null
      Throws:
      DateTimeException - if the result exceeds the supported date range

    • plusHours

      public OffsetDateTime plusHours(long hours)
      Returns a copy of this OffsetDateTime with the specified number of hours added.

      This instance is immutable and unaffected by this method call.

      Parameters:
      hours - the hours to add, may be negative
      Returns:
      an OffsetDateTime based on this date-time with the hours added, not null
      Throws:
      DateTimeException - if the result exceeds the supported date range

    • plusMinutes

      public OffsetDateTime plusMinutes(long minutes)
      Returns a copy of this OffsetDateTime with the specified number of minutes added.

      This instance is immutable and unaffected by this method call.

      Parameters:
      minutes - the minutes to add, may be negative
      Returns:
      an OffsetDateTime based on this date-time with the minutes added, not null
      Throws:
      DateTimeException - if the result exceeds the supported date range

    • plusSeconds

      public OffsetDateTime plusSeconds(long seconds)
      Returns a copy of this OffsetDateTime with the specified number of seconds added.

      This instance is immutable and unaffected by this method call.

      Parameters:
      seconds - the seconds to add, may be negative
      Returns:
      an OffsetDateTime based on this date-time with the seconds added, not null
      Throws:
      DateTimeException - if the result exceeds the supported date range

    • plusNanos

      public OffsetDateTime plusNanos(long nanos)
      Returns a copy of this OffsetDateTime with the specified number of nanoseconds added.

      This instance is immutable and unaffected by this method call.

      Parameters:
      nanos - the nanos to add, may be negative
      Returns:
      an OffsetDateTime based on this date-time with the nanoseconds added, not null
      Throws:
      DateTimeException - if the unit cannot be added to this type

    • minus

      public OffsetDateTime minus(TemporalAmount amountToSubtract)
      Returns a copy of this date-time with the specified amount subtracted.

      This returns an OffsetDateTime, based on this one, with the specified amount subtracted. The amount is typically Period or Duration but may be any other type implementing the TemporalAmount interface.

      The calculation is delegated to the amount object by calling TemporalAmount.subtractFrom(Temporal). The amount implementation is free to implement the subtraction in any way it wishes, however it typically calls back to minus(long, TemporalUnit). Consult the documentation of the amount implementation to determine if it can be successfully subtracted.

      This instance is immutable and unaffected by this method call.

      Specified by:
      minus in interface Temporal
      Parameters:
      amountToSubtract - the amount to subtract, not null
      Returns:
      an OffsetDateTime based on this date-time with the subtraction made, not null
      Throws:
      DateTimeException - if the subtraction cannot be made
      ArithmeticException - if numeric overflow occurs

    • minus

      public OffsetDateTime minus(long amountToSubtract, TemporalUnit unit)
      Returns a copy of this date-time with the specified amount subtracted.

      This returns an OffsetDateTime, based on this one, with the amount in terms of the unit subtracted. If it is not possible to subtract the amount, because the unit is not supported or for some other reason, an exception is thrown.

      This method is equivalent to plus(long, TemporalUnit) with the amount negated. See that method for a full description of how addition, and thus subtraction, works.

      This instance is immutable and unaffected by this method call.

      Specified by:
      minus in interface Temporal
      Parameters:
      amountToSubtract - the amount of the unit to subtract from the result, may be negative
      unit - the unit of the amount to subtract, not null
      Returns:
      an OffsetDateTime based on this date-time with the specified amount subtracted, not null
      Throws:
      DateTimeException - if the subtraction cannot be made
      UnsupportedTemporalTypeException - if the unit is not supported
      ArithmeticException - if numeric overflow occurs

    • minusYears

      public OffsetDateTime minusYears(long years)
      Returns a copy of this OffsetDateTime with the specified number of years subtracted.

      This method subtracts the specified amount from the years field in three steps:

      1. Subtract the input years from the year field
      2. Check if the resulting date would be invalid
      3. Adjust the day-of-month to the last valid day if necessary

      For example, 2008-02-29 (leap year) minus one year would result in the invalid date 2007-02-29 (standard year). Instead of returning an invalid result, the last valid day of the month, 2007-02-28, is selected instead.

      This instance is immutable and unaffected by this method call.

      Parameters:
      years - the years to subtract, may be negative
      Returns:
      an OffsetDateTime based on this date-time with the years subtracted, not null
      Throws:
      DateTimeException - if the result exceeds the supported date range

    • minusMonths

      public OffsetDateTime minusMonths(long months)
      Returns a copy of this OffsetDateTime with the specified number of months subtracted.

      This method subtracts the specified amount from the months field in three steps:

      1. Subtract the input months from the month-of-year field
      2. Check if the resulting date would be invalid
      3. Adjust the day-of-month to the last valid day if necessary

      For example, 2007-03-31 minus one month would result in the invalid date 2007-02-31. Instead of returning an invalid result, the last valid day of the month, 2007-02-28, is selected instead.

      This instance is immutable and unaffected by this method call.

      Parameters:
      months - the months to subtract, may be negative
      Returns:
      an OffsetDateTime based on this date-time with the months subtracted, not null
      Throws:
      DateTimeException - if the result exceeds the supported date range

    • minusWeeks

      public OffsetDateTime minusWeeks(long weeks)
      Returns a copy of this OffsetDateTime with the specified number of weeks subtracted.

      This method subtracts the specified amount in weeks from the days field decrementing the month and year fields as necessary to ensure the result remains valid. The result is only invalid if the maximum/minimum year is exceeded.

      For example, 2009-01-07 minus one week would result in 2008-12-31.

      This instance is immutable and unaffected by this method call.

      Parameters:
      weeks - the weeks to subtract, may be negative
      Returns:
      an OffsetDateTime based on this date-time with the weeks subtracted, not null
      Throws:
      DateTimeException - if the result exceeds the supported date range

    • minusDays

      public OffsetDateTime minusDays(long days)
      Returns a copy of this OffsetDateTime with the specified number of days subtracted.

      This method subtracts the specified amount from the days field decrementing the month and year fields as necessary to ensure the result remains valid. The result is only invalid if the maximum/minimum year is exceeded.

      For example, 2009-01-01 minus one day would result in 2008-12-31.

      This instance is immutable and unaffected by this method call.

      Parameters:
      days - the days to subtract, may be negative
      Returns:
      an OffsetDateTime based on this date-time with the days subtracted, not null
      Throws:
      DateTimeException - if the result exceeds the supported date range

    • minusHours

      public OffsetDateTime minusHours(long hours)
      Returns a copy of this OffsetDateTime with the specified number of hours subtracted.

      This instance is immutable and unaffected by this method call.

      Parameters:
      hours - the hours to subtract, may be negative
      Returns:
      an OffsetDateTime based on this date-time with the hours subtracted, not null
      Throws:
      DateTimeException - if the result exceeds the supported date range

    • minusMinutes

      public OffsetDateTime minusMinutes(long minutes)
      Returns a copy of this OffsetDateTime with the specified number of minutes subtracted.

      This instance is immutable and unaffected by this method call.

      Parameters:
      minutes - the minutes to subtract, may be negative
      Returns:
      an OffsetDateTime based on this date-time with the minutes subtracted, not null
      Throws:
      DateTimeException - if the result exceeds the supported date range

    • minusSeconds

      public OffsetDateTime minusSeconds(long seconds)
      Returns a copy of this OffsetDateTime with the specified number of seconds subtracted.

      This instance is immutable and unaffected by this method call.

      Parameters:
      seconds - the seconds to subtract, may be negative
      Returns:
      an OffsetDateTime based on this date-time with the seconds subtracted, not null
      Throws:
      DateTimeException - if the result exceeds the supported date range

    • minusNanos

      public OffsetDateTime minusNanos(long nanos)
      Returns a copy of this OffsetDateTime with the specified number of nanoseconds subtracted.

      This instance is immutable and unaffected by this method call.

      Parameters:
      nanos - the nanos to subtract, may be negative
      Returns:
      an OffsetDateTime based on this date-time with the nanoseconds subtracted, not null
      Throws:
      DateTimeException - if the result exceeds the supported date range

    • query

      public <R> R query(TemporalQuery<R> query)
      Queries this date-time using the specified query.

      This queries this date-time using the specified query strategy object. The TemporalQuery object defines the logic to be used to obtain the result. Read the documentation of the query to understand what the result of this method will be.

      The result of this method is obtained by invoking the TemporalQuery.queryFrom(TemporalAccessor) method on the specified query passing this as the argument.

      Specified by:
      query in interface TemporalAccessor
      Type Parameters:
      R - the type of the result
      Parameters:
      query - the query to invoke, not null
      Returns:
      the query result, null may be returned (defined by the query)
      Throws:
      DateTimeException - if unable to query (defined by the query)
      ArithmeticException - if numeric overflow occurs (defined by the query)

    • adjustInto

      public Temporal adjustInto(Temporal temporal)
      Adjusts the specified temporal object to have the same offset, date and time as this object.

      This returns a temporal object of the same observable type as the input with the offset, date and time changed to be the same as this.

      The adjustment is equivalent to using Temporal.with(TemporalField, long) three times, passing ChronoField.EPOCH_DAY, ChronoField.NANO_OF_DAY and ChronoField.OFFSET_SECONDS as the fields.

      In most cases, it is clearer to reverse the calling pattern by using Temporal.with(TemporalAdjuster): 

         // these two lines are equivalent, but the second approach is recommended
   temporal = thisOffsetDateTime.adjustInto(temporal);
   temporal = temporal.with(thisOffsetDateTime);

      This instance is immutable and unaffected by this method call.

      Specified by:
      adjustInto in interface TemporalAdjuster
      Parameters:
      temporal - the target object to be adjusted, not null
      Returns:
      the adjusted object, not null
      Throws:
      DateTimeException - if unable to make the adjustment
      ArithmeticException - if numeric overflow occurs

    • until

      public long until(Temporal endExclusive, TemporalUnit unit)
      Calculates the amount of time until another date-time in terms of the specified unit.

      This calculates the amount of time between two OffsetDateTime objects in terms of a single TemporalUnit. The start and end points are this and the specified date-time. The result will be negative if the end is before the start. For example, the amount in days between two date-times can be calculated using startDateTime.until(endDateTime, DAYS).

      The Temporal passed to this method is converted to a OffsetDateTime using from(TemporalAccessor). If the offset differs between the two date-times, the specified end date-time is normalized to have the same offset as this date-time.

      The calculation returns a whole number, representing the number of complete units between the two date-times. For example, the amount in months between 2012-06-15T00:00Z and 2012-08-14T23:59Z will only be one month as it is one minute short of two months.

      There are two equivalent ways of using this method. The first is to invoke this method. The second is to use TemporalUnit.between(Temporal, Temporal): 

         // these two lines are equivalent
   amount = start.until(end, MONTHS);
   amount = MONTHS.between(start, end);
      The choice should be made based on which makes the code more readable.

      The calculation is implemented in this method for ChronoUnit. The units NANOS, MICROS, MILLIS, SECONDS, MINUTES, HOURS and HALF_DAYS, DAYS, WEEKS, MONTHS, YEARS, DECADES, CENTURIES, MILLENNIA and ERAS are supported. Other ChronoUnit values will throw an exception.

      If the unit is not a ChronoUnit, then the result of this method is obtained by invoking TemporalUnit.between(Temporal, Temporal) passing this as the first argument and the converted input temporal as the second argument.

      This instance is immutable and unaffected by this method call.

      Specified by:
      until in interface Temporal
      Parameters:
      endExclusive - the end date, exclusive, which is converted to an OffsetDateTime, not null
      unit - the unit to measure the amount in, not null
      Returns:
      the amount of time between this date-time and the end date-time
      Throws:
      DateTimeException - if the amount cannot be calculated, or the end temporal cannot be converted to an OffsetDateTime
      UnsupportedTemporalTypeException - if the unit is not supported
      ArithmeticException - if numeric overflow occurs

    • format

      public String format(DateTimeFormatter formatter)
      Formats this date-time using the specified formatter.

      This date-time will be passed to the formatter to produce a string.

      Parameters:
      formatter - the formatter to use, not null
      Returns:
      the formatted date-time string, not null
      Throws:
      DateTimeException - if an error occurs during printing

    • atZoneSameInstant

      public ZonedDateTime atZoneSameInstant(ZoneId zone)
      Combines this date-time with a time-zone to create a ZonedDateTime ensuring that the result has the same instant.

      This returns a ZonedDateTime formed from this date-time and the specified time-zone. This conversion will ignore the visible local date-time and use the underlying instant instead. This avoids any problems with local time-line gaps or overlaps. The result might have different values for fields such as hour, minute an even day.

      To attempt to retain the values of the fields, use atZoneSimilarLocal(ZoneId). To use the offset as the zone ID, use toZonedDateTime().

      Parameters:
      zone - the time-zone to use, not null
      Returns:
      the zoned date-time formed from this date-time, not null

    • atZoneSimilarLocal

      public ZonedDateTime atZoneSimilarLocal(ZoneId zone)
      Combines this date-time with a time-zone to create a ZonedDateTime trying to keep the same local date and time.

      This returns a ZonedDateTime formed from this date-time and the specified time-zone. Where possible, the result will have the same local date-time as this object.

      Time-zone rules, such as daylight savings, mean that not every time on the local time-line exists. If the local date-time is in a gap or overlap according to the rules then a resolver is used to determine the resultant local time and offset. This method uses ZonedDateTime.ofLocal(LocalDateTime, ZoneId, ZoneOffset) to retain the offset from this instance if possible.

      Finer control over gaps and overlaps is available in two ways. If you simply want to use the later offset at overlaps then call ZonedDateTime.withLaterOffsetAtOverlap() immediately after this method.

      To create a zoned date-time at the same instant irrespective of the local time-line, use atZoneSameInstant(ZoneId). To use the offset as the zone ID, use toZonedDateTime().

      Parameters:
      zone - the time-zone to use, not null
      Returns:
      the zoned date-time formed from this date and the earliest valid time for the zone, not null

    • toOffsetTime

      public OffsetTime toOffsetTime()
      Converts this date-time to an OffsetTime.

      This returns an offset time with the same local time and offset.

      Returns:
      an OffsetTime representing the time and offset, not null

    • toZonedDateTime

      public ZonedDateTime toZonedDateTime()
      Converts this date-time to a ZonedDateTime using the offset as the zone ID.

      This creates the simplest possible ZonedDateTime using the offset as the zone ID.

      To control the time-zone used, see atZoneSameInstant(ZoneId) and atZoneSimilarLocal(ZoneId).

      Returns:
      a zoned date-time representing the same local date-time and offset, not null

    • toInstant

      public Instant toInstant()
      Converts this date-time to an Instant.

      This returns an Instant representing the same point on the time-line as this date-time.

      Returns:
      an Instant representing the same instant, not null

    • toEpochSecond

      public long toEpochSecond()
      Converts this date-time to the number of seconds from the epoch of 1970-01-01T00:00:00Z.

      This allows this date-time to be converted to a value of the epoch-seconds field. This is primarily intended for low-level conversions rather than general application usage.

      Returns:
      the number of seconds from the epoch of 1970-01-01T00:00:00Z

    • compareTo

      public int compareTo(OffsetDateTime other)
      Compares this date-time to another date-time.

      The comparison is based on the instant then on the local date-time. It is "consistent with equals", as defined by Comparable.

      For example, the following is the comparator order:

      1. 2008-12-03T10:30+01:00
      2. 2008-12-03T11:00+01:00
      3. 2008-12-03T12:00+02:00
      4. 2008-12-03T11:30+01:00
      5. 2008-12-03T12:00+01:00
      6. 2008-12-03T12:30+01:00
      Values #2 and #3 represent the same instant on the time-line. When two values represent the same instant, the local date-time is compared to distinguish them. This step is needed to make the ordering consistent with equals().
      Specified by:
      compareTo in interface Comparable<OffsetDateTime>
      Parameters:
      other - the other date-time to compare to, not null
      Returns:
      the comparator value, that is the comparison with the other's instant, if they are not equal; and if equal to the other's instant, the comparison of the other's local date-time
      See Also:

    • isAfter

      public boolean isAfter(OffsetDateTime other)
      Checks if the instant of this date-time is after that of the specified date-time.

      This method differs from the comparison in compareTo(java.time.OffsetDateTime) and equals(java.lang.Object) in that it only compares the instant of the date-time. This is equivalent to using dateTime1.toInstant().isAfter(dateTime2.toInstant());.

      Parameters:
      other - the other date-time to compare to, not null
      Returns:
      true if this is after the instant of the specified date-time

    • isBefore

      public boolean isBefore(OffsetDateTime other)
      Checks if the instant of this date-time is before that of the specified date-time.

      This method differs from the comparison in compareTo(java.time.OffsetDateTime) in that it only compares the instant of the date-time. This is equivalent to using dateTime1.toInstant().isBefore(dateTime2.toInstant());.

      Parameters:
      other - the other date-time to compare to, not null
      Returns:
      true if this is before the instant of the specified date-time

    • isEqual

      public boolean isEqual(OffsetDateTime other)
      Checks if the instant of this date-time is equal to that of the specified date-time.

      This method differs from the comparison in compareTo(java.time.OffsetDateTime) and equals(java.lang.Object) in that it only compares the instant of the date-time. This is equivalent to using dateTime1.toInstant().equals(dateTime2.toInstant());.

      Parameters:
      other - the other date-time to compare to, not null
      Returns:
      true if the instant equals the instant of the specified date-time

    • equals

      public boolean equals(Object obj)
      Checks if this date-time is equal to another date-time.

      The comparison is based on the local date-time and the offset. To compare for the same instant on the time-line, use isEqual(java.time.OffsetDateTime). Only objects of type OffsetDateTime are compared, other types return false.

      Overrides:
      equals in class Object
      Parameters:
      obj - the object to check, null returns false
      Returns:
      true if this is equal to the other date-time
      See Also:

    • hashCode

      public int hashCode()
      A hash code for this date-time.
      Overrides:
      hashCode in class Object
      Returns:
      a suitable hash code
      See Also:

    • toString

      public String toString()
      Outputs this date-time as a String, such as 2007-12-03T10:15:30+01:00.

      The output will be one of the following formats:

      • uuuu-MM-dd'T'HH:mmXXXXX
      • uuuu-MM-dd'T'HH:mm:ssXXXXX
      • uuuu-MM-dd'T'HH:mm:ss.SSSXXXXX
      • uuuu-MM-dd'T'HH:mm:ss.SSSSSSXXXXX
      • uuuu-MM-dd'T'HH:mm:ss.SSSSSSSSSXXXXX
      The format used will be the shortest that outputs the full value of the time where the omitted parts are implied to be zero. The output is compatible with ISO 8601 if the seconds in the offset are zero.
      Overrides:
      toString in class Object
      Returns:
      a string representation of this date-time, not null