ZonedDateTime

public final class ZonedDateTime extends Object
implements Temporal ChronoZonedDateTime<LocalDate> Serializable

A date-time with a time-zone in the ISO-8601 calendar system, such as 2007-12-03T10:15:30+01:00 Europe/Paris.

ZonedDateTime is an immutable representation of a date-time with a time-zone. This class stores all date and time fields, to a precision of nanoseconds, and a time-zone, with a zone offset used to handle ambiguous local date-times. For example, the value "2nd October 2007 at 13:45.30.123456789 +02:00 in the Europe/Paris time-zone" can be stored in a ZonedDateTime.

This class handles conversion from the local time-line of LocalDateTime to the instant time-line of Instant. The difference between the two time-lines is the offset from UTC/Greenwich, represented by a ZoneOffset.

Converting between the two time-lines involves calculating the offset using the rules accessed from the ZoneId. Obtaining the offset for an instant is simple, as there is exactly one valid offset for each instant. By contrast, obtaining the offset for a local date-time is not straightforward. There are three cases:

• Normal, with one valid offset. For the vast majority of the year, the normal case applies, where there is a single valid offset for the local date-time.
• Gap, with zero valid offsets. This is when clocks jump forward typically due to the spring daylight savings change from "winter" to "summer". In a gap there are local date-time values with no valid offset.
• Overlap, with two valid offsets. This is when clocks are set back typically due to the autumn daylight savings change from "summer" to "winter". In an overlap there are local date-time values with two valid offsets.

Any method that converts directly or implicitly from a local date-time to an instant by obtaining the offset has the potential to be complicated.

For Gaps, the general strategy is that if the local date-time falls in the middle of a Gap, then the resulting zoned date-time will have a local date-time shifted forwards by the length of the Gap, resulting in a date-time in the later offset, typically "summer" time.

For Overlaps, the general strategy is that if the local date-time falls in the middle of an Overlap, then the previous offset will be retained. If there is no previous offset, or the previous offset is invalid, then the earlier offset is used, typically "summer" time.. Two additional methods, withEarlierOffsetAtOverlap() and withLaterOffsetAtOverlap(), help manage the case of an overlap.

In terms of design, this class should be viewed primarily as the combination of a LocalDateTime and a ZoneId. The ZoneOffset is a vital, but secondary, piece of information, used to ensure that the class represents an instant, especially during a daylight savings overlap.

Public Method Summary

boolean	equals(Object obj) Checks if this date-time is equal to another date-time.
String	format(DateTimeFormatter formatter) Formats this date-time using the specified formatter.
static ZonedDateTime	from(TemporalAccessor temporal) Obtains an instance of ZonedDateTime from a temporal object.
int	get(TemporalField field) Gets the value of the specified field from this date-time as an int.
int	getDayOfMonth() Gets the day-of-month field.
DayOfWeek	getDayOfWeek() Gets the day-of-week field, which is an enum DayOfWeek.
int	getDayOfYear() Gets the day-of-year field.
int	getHour() Gets the hour-of-day field.
long	getLong(TemporalField field) Gets the value of the specified field from this date-time as a long.
int	getMinute() Gets the minute-of-hour field.
Month	getMonth() Gets the month-of-year field using the Month enum.
int	getMonthValue() Gets the month-of-year field from 1 to 12.
int	getNano() Gets the nano-of-second field.
ZoneOffset	getOffset() Gets the zone offset, such as '+01:00'.
int	getSecond() Gets the second-of-minute field.
int	getYear() Gets the year field.
ZoneId	getZone() Gets the time-zone, such as 'Europe/Paris'.
int	hashCode() A hash code for this date-time.
boolean	isSupported(TemporalUnit unit) Checks if the specified unit is supported.
boolean	isSupported(TemporalField field) Checks if the specified field is supported.
ZonedDateTime	minus(TemporalAmount amountToSubtract) Returns a copy of this date-time with the specified amount subtracted.
ZonedDateTime	minus(long amountToSubtract, TemporalUnit unit) Returns a copy of this date-time with the specified amount subtracted.
ZonedDateTime	minusDays(long days) Returns a copy of this ZonedDateTime with the specified number of days subtracted.
ZonedDateTime	minusHours(long hours) Returns a copy of this ZonedDateTime with the specified number of hours subtracted.
ZonedDateTime	minusMinutes(long minutes) Returns a copy of this ZonedDateTime with the specified number of minutes subtracted.
ZonedDateTime	minusMonths(long months) Returns a copy of this ZonedDateTime with the specified number of months subtracted.
ZonedDateTime	minusNanos(long nanos) Returns a copy of this ZonedDateTime with the specified number of nanoseconds subtracted.
ZonedDateTime	minusSeconds(long seconds) Returns a copy of this ZonedDateTime with the specified number of seconds subtracted.
ZonedDateTime	minusWeeks(long weeks) Returns a copy of this ZonedDateTime with the specified number of weeks subtracted.
ZonedDateTime	minusYears(long years) Returns a copy of this ZonedDateTime with the specified number of years subtracted.
static ZonedDateTime	now(ZoneId zone) Obtains the current date-time from the system clock in the specified time-zone.
static ZonedDateTime	now() Obtains the current date-time from the system clock in the default time-zone.
static ZonedDateTime	now(Clock clock) Obtains the current date-time from the specified clock.
static ZonedDateTime	of(LocalDateTime localDateTime, ZoneId zone) Obtains an instance of ZonedDateTime from a local date-time.
static ZonedDateTime	of(int year, int month, int dayOfMonth, int hour, int minute, int second, int nanoOfSecond, ZoneId zone) Obtains an instance of ZonedDateTime from a year, month, day, hour, minute, second, nanosecond and time-zone.
static ZonedDateTime	of(LocalDate date, LocalTime time, ZoneId zone) Obtains an instance of ZonedDateTime from a local date and time.
static ZonedDateTime	ofInstant(Instant instant, ZoneId zone) Obtains an instance of ZonedDateTime from an Instant.
static ZonedDateTime	ofInstant(LocalDateTime localDateTime, ZoneOffset offset, ZoneId zone) Obtains an instance of ZonedDateTime from the instant formed by combining the local date-time and offset.
static ZonedDateTime	ofLocal(LocalDateTime localDateTime, ZoneId zone, ZoneOffset preferredOffset) Obtains an instance of ZonedDateTime from a local date-time using the preferred offset if possible.
static ZonedDateTime	ofStrict(LocalDateTime localDateTime, ZoneOffset offset, ZoneId zone) Obtains an instance of ZonedDateTime strictly validating the combination of local date-time, offset and zone ID.
static ZonedDateTime	parse(CharSequence text, DateTimeFormatter formatter) Obtains an instance of ZonedDateTime from a text string using a specific formatter.
static ZonedDateTime	parse(CharSequence text) Obtains an instance of ZonedDateTime from a text string such as 2007-12-03T10:15:30+01:00[Europe/Paris].
ZonedDateTime	plus(TemporalAmount amountToAdd) Returns a copy of this date-time with the specified amount added.
ZonedDateTime	plus(long amountToAdd, TemporalUnit unit) Returns a copy of this date-time with the specified amount added.
ZonedDateTime	plusDays(long days) Returns a copy of this ZonedDateTime with the specified number of days added.
ZonedDateTime	plusHours(long hours) Returns a copy of this ZonedDateTime with the specified number of hours added.
ZonedDateTime	plusMinutes(long minutes) Returns a copy of this ZonedDateTime with the specified number of minutes added.
ZonedDateTime	plusMonths(long months) Returns a copy of this ZonedDateTime with the specified number of months added.
ZonedDateTime	plusNanos(long nanos) Returns a copy of this ZonedDateTime with the specified number of nanoseconds added.
ZonedDateTime	plusSeconds(long seconds) Returns a copy of this ZonedDateTime with the specified number of seconds added.
ZonedDateTime	plusWeeks(long weeks) Returns a copy of this ZonedDateTime with the specified number of weeks added.
ZonedDateTime	plusYears(long years) Returns a copy of this ZonedDateTime with the specified number of years added.
<R> R	query(TemporalQuery<R> query) Queries this date-time using the specified query.
ValueRange	range(TemporalField field) Gets the range of valid values for the specified field.
LocalDate	toLocalDate() Gets the LocalDate part of this date-time.
LocalDateTime	toLocalDateTime() Gets the LocalDateTime part of this date-time.
LocalTime	toLocalTime() Gets the LocalTime part of this date-time.
OffsetDateTime	toOffsetDateTime() Converts this date-time to an OffsetDateTime.
String	toString() Outputs this date-time as a String, such as 2007-12-03T10:15:30+01:00[Europe/Paris].
ZonedDateTime	truncatedTo(TemporalUnit unit) Returns a copy of this ZonedDateTime with the time truncated.
long	until(Temporal endExclusive, TemporalUnit unit) Calculates the amount of time until another date-time in terms of the specified unit.
ZonedDateTime	with(TemporalField field, long newValue) Returns a copy of this date-time with the specified field set to a new value.
ZonedDateTime	with(TemporalAdjuster adjuster) Returns an adjusted copy of this date-time.
ZonedDateTime	withDayOfMonth(int dayOfMonth) Returns a copy of this ZonedDateTime with the day-of-month altered.
ZonedDateTime	withDayOfYear(int dayOfYear) Returns a copy of this ZonedDateTime with the day-of-year altered.
ZonedDateTime	withEarlierOffsetAtOverlap() Returns a copy of this date-time changing the zone offset to the earlier of the two valid offsets at a local time-line overlap.
ZonedDateTime	withFixedOffsetZone() Returns a copy of this date-time with the zone ID set to the offset.
ZonedDateTime	withHour(int hour) Returns a copy of this ZonedDateTime with the hour-of-day altered.
ZonedDateTime	withLaterOffsetAtOverlap() Returns a copy of this date-time changing the zone offset to the later of the two valid offsets at a local time-line overlap.
ZonedDateTime	withMinute(int minute) Returns a copy of this ZonedDateTime with the minute-of-hour altered.
ZonedDateTime	withMonth(int month) Returns a copy of this ZonedDateTime with the month-of-year altered.
ZonedDateTime	withNano(int nanoOfSecond) Returns a copy of this ZonedDateTime with the nano-of-second altered.
ZonedDateTime	withSecond(int second) Returns a copy of this ZonedDateTime with the second-of-minute altered.
ZonedDateTime	withYear(int year) Returns a copy of this ZonedDateTime with the year altered.
ZonedDateTime	withZoneSameInstant(ZoneId zone) Returns a copy of this date-time with a different time-zone, retaining the instant.
ZonedDateTime	withZoneSameLocal(ZoneId zone) Returns a copy of this date-time with a different time-zone, retaining the local date-time if possible.

Inherited Method Summary

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

From interface java.time.temporal.Temporal

abstract boolean	isSupported(TemporalUnit unit) Checks if the specified unit is supported.
Temporal	minus(TemporalAmount amount) Returns an object of the same type as this object with an amount subtracted.
Temporal	minus(long amountToSubtract, TemporalUnit unit) Returns an object of the same type as this object with the specified period subtracted.
abstract Temporal	plus(long amountToAdd, TemporalUnit unit) Returns an object of the same type as this object with the specified period added.
Temporal	plus(TemporalAmount amount) Returns an object of the same type as this object with an amount added.
abstract long	until(Temporal endExclusive, TemporalUnit unit) Calculates the amount of time until another temporal in terms of the specified unit.
abstract Temporal	with(TemporalField field, long newValue) Returns an object of the same type as this object with the specified field altered.
Temporal	with(TemporalAdjuster adjuster) Returns an adjusted object of the same type as this object with the adjustment made.

From interface java.time.chrono.ChronoZonedDateTime

int	compareTo(ChronoZonedDateTime<?> other) Compares this date-time to another date-time, including the chronology.
abstract boolean	equals(Object obj) Checks if this date-time is equal to another date-time.
String	format(DateTimeFormatter formatter) Formats this date-time using the specified formatter.
static ChronoZonedDateTime<?>	from(TemporalAccessor temporal) Obtains an instance of ChronoZonedDateTime from a temporal object.
int	get(TemporalField field) Gets the value of the specified field as an int.
Chronology	getChronology() Gets the chronology of this date-time.
long	getLong(TemporalField field) Gets the value of the specified field as a long.
abstract ZoneOffset	getOffset() Gets the zone offset, such as '+01:00'.
abstract ZoneId	getZone() Gets the zone ID, such as 'Europe/Paris'.
abstract int	hashCode() A hash code for this date-time.
boolean	isAfter(ChronoZonedDateTime<?> other) Checks if the instant of this date-time is after that of the specified date-time.
boolean	isBefore(ChronoZonedDateTime<?> other) Checks if the instant of this date-time is before that of the specified date-time.
boolean	isEqual(ChronoZonedDateTime<?> other) Checks if the instant of this date-time is equal to that of the specified date-time.
boolean	isSupported(TemporalUnit unit) Checks if the specified unit is supported.
abstract boolean	isSupported(TemporalField field) Checks if the specified field is supported.
ChronoZonedDateTime<D>	minus(TemporalAmount amount) Returns an object of the same type as this object with an amount subtracted.
ChronoZonedDateTime<D>	minus(long amountToSubtract, TemporalUnit unit) Returns an object of the same type as this object with the specified period subtracted.
ChronoZonedDateTime<D>	plus(TemporalAmount amount) Returns an object of the same type as this object with an amount added.
abstract ChronoZonedDateTime<D>	plus(long amountToAdd, TemporalUnit unit) Returns an object of the same type as this object with the specified period added.
<R> R	query(TemporalQuery<R> query) Queries this date-time using the specified query.
ValueRange	range(TemporalField field) Gets the range of valid values for the specified field.
static Comparator<ChronoZonedDateTime<?>>	timeLineOrder() Gets a comparator that compares ChronoZonedDateTime in time-line order ignoring the chronology.
long	toEpochSecond() Converts this date-time to the number of seconds from the epoch of 1970-01-01T00:00:00Z.
Instant	toInstant() Converts this date-time to an Instant.
D	toLocalDate() Gets the local date part of this date-time.
abstract ChronoLocalDateTime<D>	toLocalDateTime() Gets the local date-time part of this date-time.
LocalTime	toLocalTime() Gets the local time part of this date-time.
abstract String	toString() Outputs this date-time as a String.
abstract ChronoZonedDateTime<D>	with(TemporalField field, long newValue) Returns an object of the same type as this object with the specified field altered.
ChronoZonedDateTime<D>	with(TemporalAdjuster adjuster) Returns an adjusted object of the same type as this object with the adjustment made.
abstract ChronoZonedDateTime<D>	withEarlierOffsetAtOverlap() Returns a copy of this date-time changing the zone offset to the earlier of the two valid offsets at a local time-line overlap.
abstract ChronoZonedDateTime<D>	withLaterOffsetAtOverlap() Returns a copy of this date-time changing the zone offset to the later of the two valid offsets at a local time-line overlap.
abstract ChronoZonedDateTime<D>	withZoneSameInstant(ZoneId zone) Returns a copy of this date-time with a different time-zone, retaining the instant.
abstract ChronoZonedDateTime<D>	withZoneSameLocal(ZoneId zone) Returns a copy of this date-time with a different time-zone, retaining the local date-time if possible.

From interface java.time.temporal.TemporalAccessor

int	get(TemporalField field) Gets the value of the specified field as an int.
abstract long	getLong(TemporalField field) Gets the value of the specified field as a long.
abstract boolean	isSupported(TemporalField field) Checks if the specified field is supported.
<R> R	query(TemporalQuery<R> query) Queries this date-time.
ValueRange	range(TemporalField field) Gets the range of valid values for the specified field.

From interface java.lang.Comparable

abstract int

compareTo(ChronoZonedDateTime<?> o) Compares this object with the specified object for order.

Public Methods

public boolean equals (Object obj)

Checks if this date-time is equal to another date-time.

The comparison is based on the offset date-time and the zone. Only objects of type ZonedDateTime are compared, other types return false.

Parameters

obj	the object to check, null returns false

Returns

• true if this is equal to the other date-time

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

public static ZonedDateTime from (TemporalAccessor temporal)

Obtains an instance of ZonedDateTime from a temporal object.

This obtains a zoned 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 ZonedDateTime.

The conversion will first obtain a ZoneId from the temporal object, falling back to a ZoneOffset if necessary. It will then try to obtain an Instant, falling back to a LocalDateTime if necessary. The result will be either the combination of ZoneId or ZoneOffset with Instant or LocalDateTime. 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, ZonedDateTime::from.

Parameters

temporal	the temporal object to convert, not null

Returns

• the zoned date-time, not null

Throws

DateTimeException	if unable to convert to an ZonedDateTime

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 a DateTimeException. 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.

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

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

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

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

public int getHour ()

Gets the hour-of-day field.

Returns

• the hour-of-day, from 0 to 23

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.

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

public int getMinute ()

Gets the minute-of-hour field.

Returns

• the minute-of-hour, from 0 to 59

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

• 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 int getNano ()

Gets the nano-of-second field.

Returns

• the nano-of-second, from 0 to 999,999,999

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

public int getSecond ()

Gets the second-of-minute field.

Returns

• the second-of-minute, from 0 to 59

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

public ZoneId getZone ()

Gets the time-zone, such as 'Europe/Paris'.

This returns the zone ID. This identifies the time-zone rules that determine when and how the offset from UTC/Greenwich changes.

The zone ID may be same as the {@linkplain #getOffset() offset}. If this is true, then any future calculations, such as addition or subtraction, have no complex edge cases due to time-zone rules. See also withFixedOffsetZone().

Returns

• the time-zone, not null

public int hashCode ()

A hash code for this date-time.

Returns

• a suitable hash code

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.

Parameters

unit	the unit to check, null returns false

Returns

• true if the unit can be added/subtracted, false if not

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.

Parameters

field	the field to check, null returns false

Returns

• true if the field is supported on this date-time, false if not

public ZonedDateTime minus (TemporalAmount amountToSubtract)

Returns a copy of this date-time with the specified amount subtracted.

This returns a ZonedDateTime, 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.

Parameters

amountToSubtract	the amount to subtract, not null

Returns

• a ZonedDateTime based on this date-time with the subtraction made, not null

Throws

DateTimeException	if the subtraction cannot be made
ArithmeticException	if numeric overflow occurs

public ZonedDateTime minus (long amountToSubtract, TemporalUnit unit)

Returns a copy of this date-time with the specified amount subtracted.

This returns a ZonedDateTime, 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.

The calculation for date and time units differ.

Date units operate on the local time-line. The period is first subtracted from the local date-time, then converted back to a zoned date-time using the zone ID. The conversion uses ofLocal(LocalDateTime, ZoneId, ZoneOffset) with the offset before the subtraction.

Time units operate on the instant time-line. The period is first subtracted from the local date-time, then converted back to a zoned date-time using the zone ID. The conversion uses ofInstant(LocalDateTime, ZoneOffset, ZoneId) with the offset before the subtraction.

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.

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

• a ZonedDateTime 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

public ZonedDateTime minusDays (long days)

Returns a copy of this ZonedDateTime with the specified number of days subtracted.

This operates on the local time-line, subtracting days to the local date-time. This is then converted back to a ZonedDateTime, using the zone ID to obtain the offset.

When converting back to ZonedDateTime, if the local date-time is in an overlap, then the offset will be retained if possible, otherwise the earlier offset will be used. If in a gap, the local date-time will be adjusted forward by the length of the gap.

This instance is immutable and unaffected by this method call.

Parameters

days	the days to subtract, may be negative

Returns

• a ZonedDateTime based on this date-time with the days subtracted, not null

Throws

DateTimeException	if the result exceeds the supported date range

public ZonedDateTime minusHours (long hours)

Returns a copy of this ZonedDateTime with the specified number of hours subtracted.

This operates on the instant time-line, such that subtracting one hour will always be a duration of one hour earlier. This may cause the local date-time to change by an amount other than one hour. Note that this is a different approach to that used by days, months and years, thus subtracting one day is not the same as adding 24 hours.

For example, consider a time-zone where the spring DST cutover means that the local times 01:00 to 01:59 occur twice changing from offset +02:00 to +01:00.

• Subtracting one hour from 02:30+01:00 will result in 01:30+02:00
• Subtracting one hour from 01:30+01:00 will result in 01:30+02:00
• Subtracting one hour from 01:30+02:00 will result in 00:30+01:00
• Subtracting three hours from 02:30+01:00 will result in 00:30+02:00

This instance is immutable and unaffected by this method call.

Parameters