TemporalUnit

Returns a copy of the specified temporal object with the specified period added.

The period added is a multiple of this unit. For example, this method could be used to add "3 days" to a date by calling this method on the instance representing "days", passing the date and the period "3". The period to be added may be negative, which is equivalent to subtraction.

There are two equivalent ways of using this method. The first is to invoke this method directly. The second is to use Temporal#plus:

  // these two lines are equivalent, but the second approach is recommended
  temporal = thisUnit.doPlus(temporal);
  temporal = temporal.plus(thisUnit);

It is recommended to use the second approach, plus, as it is a lot clearer to read in code.

Implementations should perform any queries or calculations using the units available in ChronoUnit or the fields available in ChronoField. If the field is not supported a DateTimeException must be thrown.

Implementations must not alter the specified temporal object. Instead, an adjusted copy of the original must be returned. This provides equivalent, safe behavior for immutable and mutable implementations.

Throw:

*	DateTimeException if the period cannot be added.

Calculates the period in terms of this unit between two temporal objects of the same type.

This calculates the period between two temporals in terms of this unit. The start and end points are supplied as temporal objects and must be of the same type. The result will be negative if the end is before the start. For example, the period in hours between two temporal objects can be calculated using HOURS.between.

The calculation returns a whole number, representing the number of complete units between the two temporals. For example, the period in hours between the times 11:30 and 13:29 will only be one hour as it is one minute short of two hours.

There are two equivalent ways of using this method. The first is to invoke this method directly. The second is to use Temporal#until:

  // these two lines are equivalent
  between = thisUnit.between(start, end);
  between = start.until(end, thisUnit);

The choice should be made based on which makes the code more readable.

For example, this method allows the number of days between two dates to be calculated:

  long daysBetween = DAYS.between(start, end);
  // or alternatively
  long daysBetween = start.until(end, DAYS);

Implementations should perform any queries or calculations using the units available in ChronoUnit or the fields available in ChronoField. If the unit is not supported a DateTimeException must be thrown. Implementations must not alter the specified temporal objects.

Throw:

*	DateTimeException if the period cannot be calculated.
*	ArithmeticException if numeric overflow occurs.

Gets the duration of this unit, which may be an estimate.

All units return a duration measured in standard nanoseconds from this method. The duration will be positive and non-zero. For example, an hour has a duration of 60 * 60 * 1,000,000,000 ns.

Some units may return an accurate duration while others return an estimate. For example, days have an estimated duration due to the possibility of daylight saving time changes. To determine if the duration is an estimate, use isDurationEstimated.

Checks if this unit is date-based.

Checks if the duration of the unit is an estimate.

All units have a duration, however the duration is not always accurate. For example, days have an estimated duration due to the possibility of daylight saving time changes. This method returns true if the duration is an estimate and false if it is accurate. Note that accurate/estimated ignores leap seconds.

Checks if this unit is supported by the specified temporal object.

This checks that the implementing date-time can add/subtract this unit. This can be used to avoid throwing an exception.

Checks if this unit is time-based.