Year

Obtains an instance of Year from a temporal object.

A TemporalAccessor represents some form of date and time information. This factory converts the arbitrary temporal object to an instance of Year.

The conversion extracts the ChronoField#YEAR field. The extraction is only permitted if the temporal object has an ISO chronology, or can be converted to a LocalDate.

This method matches the signature of the functional interface TemporalQuery allowing it to be used in queries via method reference, Year::from.

Throw:

Checks if the year is a leap year, according to the ISO proleptic calendar system rules.

This method applies the current rules for leap years across the whole time-line. In general, a year is a leap year if it is divisible by four without remainder. However, years divisible by 100, are not leap years, with the exception of years divisible by 400 which are.

For example, 1904 is a leap year it is divisible by 4. 1900 was not a leap year as it is divisible by 100, however 2000 was a leap year as it is divisible by 400.

The calculation is proleptic - applying the same rules into the far future and far past. This is historically inaccurate, but is correct for the ISO-8601 standard.

function overloading for Year.now

if called without arguments, then Year.now0 is executed.

if called with 1 arguments and first argument is an instance of ZoneId, then Year.nowZoneId is executed.

Otherwise Year.nowClock is executed.

Obtains the current year from the system clock in the default time-zone.

This will query the system clock (see Clock#systemDefaultZone) in the default time-zone to obtain the current year.

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

Obtains the current year from the specified clock.

This will query the specified clock to obtain the current year. Using this method allows the use of an alternate clock for testing. The alternate clock may be introduced using dependency injection.

Obtains the current year from the system clock in the specified time-zone.

This will query the system clock (see Clock#system) to obtain the current year. Specifying the time-zone avoids dependence on the default time-zone.

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

Obtains an instance of Year.

This method accepts a year value from the proleptic ISO calendar system.

• The year 2AD/CE is represented by 2.
• The year 1AD/CE is represented by 1.
• The year 1BC/BCE is represented by 0.
• The year 2BC/BCE is represented by -1.

Throw:

function overloading for Year.parse

if called with 1 argument, then Year.parseText is executed.

Otherwise Year.parseTextFormatter is executed.

Obtains an instance of Year from a text string such as 2007.

The string must represent a valid year. Years outside the range 0000 to 9999 must be prefixed by the plus or minus symbol.

Throw:

Obtains an instance of Year from a text string using a specific formatter.

The text is parsed using the formatter, returning a year.

Throw:

Adjusts the specified temporal object to have this year.

This returns a temporal object of the same observable type as the input with the year changed to be the same as this.

The adjustment is equivalent to using Temporal#with passing ChronoField#YEAR as the field. If the specified temporal object does not use the ISO calendar system then a DateTimeException is thrown.

In most cases, it is clearer to reverse the calling pattern by using Temporal#with:

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

This instance is immutable and unaffected by this method call.

Throw:

Combines this year with a day-of-year to create a LocalDate.

This returns a LocalDate formed from this year and the specified day-of-year.

The day-of-year value 366 is only valid in a leap year.

Throw:

function overloading for Year.atMonth

if called with 1 arguments and first argument is instance of Month, then Year.atMonthMonth is executed.

Otherwise Year.atMonthNumber is executed.

Combines this year with a month-day to create a LocalDate.

This returns a LocalDate formed from this year and the specified month-day.

A month-day of February 29th will be adjusted to February 28th in the resulting date if the year is not a leap year.

Combines this year with a month to create a YearMonth.

This returns a YearMonth formed from this year and the specified month. All possible combinations of year and month are valid.

This method can be used as part of a chain to produce a date:

 LocalDate date = year.atMonth(month).atDay(day);

Combines this year with a month to create a YearMonth.

This returns a YearMonth formed from this year and the specified month. All possible combinations of year and month are valid.

This method can be used as part of a chain to produce a date:

 LocalDate date = year.atMonth(month).atDay(day);

Throw:

Compares this year to another year.

The comparison is based on the value of the year. It is "consistent with equals", as defined by Comparable.

Checks if this year is equal to the specified Year.

The comparison is based on the value

Outputs this year as a string using the formatter.

Throw:

Gets the value of the specified field from this year as an int.

This queries this year for the value for 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 (see isSupported) will return valid values based on this year. All other ChronoField instances will throw a DateTimeException.

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

Override:

Throw:

Gets the value of the specified field from this year as a long.

This queries this year for the value for 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 (see isSupported) will return valid values based on this year. All other ChronoField instances will throw a DateTimeException.

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

Override:

Throw:

Is this year after the specified year.

Is this year before the specified year.

Checks if the year is a leap year, according to the ISO proleptic calendar system rules.

This method applies the current rules for leap years across the whole time-line. In general, a year is a leap year if it is divisible by four without remainder. However, years divisible by 100, are not leap years, with the exception of years divisible by 400 which are.

For example, 1904 is a leap year it is divisible by 4. 1900 was not a leap year as it is divisible by 100, however 2000 was a leap year as it is divisible by 400.

The calculation is proleptic - applying the same rules into the far future and far past. This is historically inaccurate, but is correct for the ISO-8601 standard.

function overloading for YearMonth.isSupported

if called with 1 argument and first argument is an instance of TemporalField, then YearMonth.isSupportedField is executed,

otherwise YearMonth.isSupportedUnit is executed

Override:

Checks if the specified field is supported.

This checks if this year can be queried for the specified field. If false, then calling range and get will throw an exception.

If the field is a ChronoField then the query is implemented here. The supported fields (see isSupported) will return valid values based on this date-time. The supported fields are:

• YEAR_OF_ERA
• YEAR
• ERA

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 passing this as the argument. Whether the field is supported is determined by the field.

Checks if the month-day is valid for this year.

This method checks whether this year and the input month and day form a valid date.

Gets the length of this year in days.

Returns a copy of this year with the specified number of years subtracted.

This instance is immutable and unaffected by this method call.

Throw:

Returns a copy of this year with the specified number of years added.

This instance is immutable and unaffected by this method call.

Throw:

Queries this year using the specified query.

This queries this year 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 method on the specified query passing this as the argument.

Override:

Throw:

Gets the range of valid values for the specified field.

The range object expresses the minimum and maximum valid values for a field. This year 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 (see isSupported) will return appropriate range instances. All other ChronoField instances will throw a DateTimeException.

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

Override:

Throw:

toJSON() use by JSON.stringify delegates to toString()

Outputs this year as a string.

Calculates the amount of time until another temporal in terms of the specified unit. This calculates the amount of time between two temporal objects in terms of a single TemporalUnit. The start and end points are this and the specified temporal. The end point is converted to be of the same type as the start point if different. The result will be negative if the end is before the start. For example, the amount in hours between two temporal objects can be calculated using startTime.until(endTime, HOURS).

The calculation returns a whole number, representing the number of complete units between the two temporals. For example, the amount 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 TemporalUnit.between(Temporal, Temporal):

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

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:

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

Implementation Requirements:

Implementations must begin by checking to ensure that the input temporal object is of the same observable type as the implementation. They must then perform the calculation for all instances of ChronoUnit. An UnsupportedTemporalTypeException must be thrown for ChronoUnit instances that are unsupported. 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.

In summary, implementations must behave in a manner equivalent to this pseudo-code:

  // convert the end temporal to the same type as this class
  if (unit instanceof ChronoUnit) {
    // if unit is supported, then calculate and return result
    // else throw UnsupportedTemporalTypeException for unsupported units
  }
  return unit.between(this, convertedEndTemporal);

Note that the unit's between method must only be invoked if the two temporal objects have exactly the same type evaluated by getClass().

Implementations must ensure that no observable state is altered when this read-only method is invoked.

Override:

Throw: