net.time4j.engine

Interface CalendarSystem<D>

Type Parameters:

D - generic type of calendar date (subtype of Calendrical or CalendarVariant)

public interface CalendarSystem<D>

Represents a calendar system which can map a calendar date to a day number corresponding to the count of days elapsed since UTC epoch [1972-01-01].

Specification: All implementations must be immutable.

Author:

Meno Hochschild

See Also:

Calendrical, CalendarVariant, EpochDays

Method Summary

Methods

Modifier and Type	Method and Description
List<CalendarEra>	getEras() Yields an enumeration of valid eras in ascending order.
long	getMaximumSinceUTC() Gets the maximum day number as count of days since the introduction of UTC [1972-01-01].
long	getMinimumSinceUTC() Gets the minimum day number as count of days since the introduction of UTC [1972-01-01].
long	transform(D date) Transforms given calendar date to a day number on the local time line at the reference time of noon.
D	transform(long utcDays) Transforms given day number to a calendar date on the local time line at the reference time of noon.

Method Detail

transform

D transform(long utcDays)

Transforms given day number to a calendar date on the local time line at the reference time of noon.

Parameters:

utcDays - count of days since UTC epoch [1972-01-01]

Returns:

new calendar date

Throws:

IllegalArgumentException - if the argument is out of range

transform

long transform(D date)

Transforms given calendar date to a day number on the local time line at the reference time of noon.

Parameters:

date - calendar date to be transformed

Returns:

count of days since UTC epoch [1972-01-01]

Throws:

IllegalArgumentException - if the argument is not consistent with this calendar system

getMinimumSinceUTC

long getMinimumSinceUTC()

Gets the minimum day number as count of days since the introduction of UTC [1972-01-01].

Returns:

smallest count of days relative to UTC epoch [1972-01-01]

See Also:

CalendarSystem.getMaximumSinceUTC()

getMaximumSinceUTC

long getMaximumSinceUTC()

Gets the maximum day number as count of days since the introduction of UTC [1972-01-01].

Returns:

largest count of days relative to UTC epoch [1972-01-01]

See Also:

CalendarSystem.getMinimumSinceUTC()

getEras

List<CalendarEra> getEras()

Yields an enumeration of valid eras in ascending order.

All ISO-systems only yield an empty list. A gregorian calendar defines the eras BC and AD related to Jesu birth however.

Returns:

unmodifiable list of eras (maybe empty)