GregorianCalendar
open class GregorianCalendar : Calendar
kotlin.Any | ||
↳ | android.icu.util.Calendar | |
↳ | android.icu.util.GregorianCalendar |
[icu enhancement] ICU's replacement for java.util.GregorianCalendar
. Methods, fields, and other functionality specific to ICU are labeled '[icu]'.
GregorianCalendar
is a concrete subclass of Calendar
and provides the standard calendar used by most of the world.
The standard (Gregorian) calendar has 2 eras, BC and AD.
This implementation handles a single discontinuity, which corresponds by default to the date the Gregorian calendar was instituted (October 15, 1582 in some countries, later in others). The cutover date may be changed by the caller by calling setGregorianChange()
.
Historically, in those countries which adopted the Gregorian calendar first, October 4, 1582 was thus followed by October 15, 1582. This calendar models this correctly. Before the Gregorian cutover, GregorianCalendar
implements the Julian calendar. The only difference between the Gregorian and the Julian calendar is the leap year rule. The Julian calendar specifies leap years every four years, whereas the Gregorian calendar omits century years which are not divisible by 400.
GregorianCalendar
implements proleptic Gregorian and Julian calendars. That is, dates are computed by extrapolating the current rules indefinitely far backward and forward in time. As a result, GregorianCalendar
may be used for all years to generate meaningful and consistent results. However, dates obtained using GregorianCalendar
are historically accurate only from March 1, 4 AD onward, when modern Julian calendar rules were adopted. Before this date, leap year rules were applied irregularly, and before 45 BC the Julian calendar did not even exist.
Prior to the institution of the Gregorian calendar, New Year's Day was March 25. To avoid confusion, this calendar always uses January 1. A manual adjustment may be made if desired for dates that are prior to the Gregorian changeover and which fall between January 1 and March 24.
Values calculated for the WEEK_OF_YEAR
field range from 1 to 53. Week 1 for a year is the earliest seven day period starting on getFirstDayOfWeek()
that contains at least getMinimalDaysInFirstWeek()
days from that year. It thus depends on the values of getMinimalDaysInFirstWeek()
, getFirstDayOfWeek()
, and the day of the week of January 1. Weeks between week 1 of one year and week 1 of the following year are numbered sequentially from 2 to 52 or 53 (as needed).
For example, January 1, 1998 was a Thursday. If getFirstDayOfWeek()
is MONDAY
and getMinimalDaysInFirstWeek()
is 4 (these are the values reflecting ISO 8601 and many national standards), then week 1 of 1998 starts on December 29, 1997, and ends on January 4, 1998. If, however, getFirstDayOfWeek()
is SUNDAY
, then week 1 of 1998 starts on January 4, 1998, and ends on January 10, 1998; the first three days of 1998 then are part of week 53 of 1997.
Values calculated for the WEEK_OF_MONTH
field range from 0 or 1 to 4 or 5. Week 1 of a month (the days with WEEK_OF_MONTH = 1
) is the earliest set of at least getMinimalDaysInFirstWeek()
contiguous days in that month, ending on the day before getFirstDayOfWeek()
. Unlike week 1 of a year, week 1 of a month may be shorter than 7 days, need not start on getFirstDayOfWeek()
, and will not include days of the previous month. Days of a month before week 1 have a WEEK_OF_MONTH
of 0.
For example, if getFirstDayOfWeek()
is SUNDAY
and getMinimalDaysInFirstWeek()
is 4, then the first week of January 1998 is Sunday, January 4 through Saturday, January 10. These days have a WEEK_OF_MONTH
of 1. Thursday, January 1 through Saturday, January 3 have a WEEK_OF_MONTH
of 0. If getMinimalDaysInFirstWeek()
is changed to 3, then January 1 through January 3 have a WEEK_OF_MONTH
of 1.
Example:
// get the supported ids for GMT-08:00 (Pacific Standard Time) String[] ids = TimeZone.getAvailableIDs(-8 * 60 * 60 * 1000); // if no ids were returned, something is wrong. get out. if (ids.length == 0) System.exit(0); // begin output System.out.println("Current Time"); // create a Pacific Standard Time time zone SimpleTimeZone pdt = new SimpleTimeZone(-8 * 60 * 60 * 1000, ids[0]); // set up rules for daylight savings time pdt.setStartRule(Calendar.MARCH, 2, Calendar.SUNDAY, 2 * 60 * 60 * 1000); pdt.setEndRule(Calendar.NOVEMBER, 1, Calendar.SUNDAY, 2 * 60 * 60 * 1000); // create a GregorianCalendar with the Pacific Daylight time zone // and the current date and time Calendar calendar = new GregorianCalendar(pdt); Date trialTime = new Date(); calendar.setTime(trialTime); // print out a bunch of interesting things System.out.println("ERA: " + calendar.get(Calendar.ERA)); System.out.println("YEAR: " + calendar.get(Calendar.YEAR)); System.out.println("MONTH: " + calendar.get(Calendar.MONTH)); System.out.println("WEEK_OF_YEAR: " + calendar.get(Calendar.WEEK_OF_YEAR)); System.out.println("WEEK_OF_MONTH: " + calendar.get(Calendar.WEEK_OF_MONTH)); System.out.println("DATE: " + calendar.get(Calendar.DATE)); System.out.println("DAY_OF_MONTH: " + calendar.get(Calendar.DAY_OF_MONTH)); System.out.println("DAY_OF_YEAR: " + calendar.get(Calendar.DAY_OF_YEAR)); System.out.println("DAY_OF_WEEK: " + calendar.get(Calendar.DAY_OF_WEEK)); System.out.println("DAY_OF_WEEK_IN_MONTH: " + calendar.get(Calendar.DAY_OF_WEEK_IN_MONTH)); System.out.println("AM_PM: " + calendar.get(Calendar.AM_PM)); System.out.println("HOUR: " + calendar.get(Calendar.HOUR)); System.out.println("HOUR_OF_DAY: " + calendar.get(Calendar.HOUR_OF_DAY)); System.out.println("MINUTE: " + calendar.get(Calendar.MINUTE)); System.out.println("SECOND: " + calendar.get(Calendar.SECOND)); System.out.println("MILLISECOND: " + calendar.get(Calendar.MILLISECOND)); System.out.println("ZONE_OFFSET: " + (calendar.get(Calendar.ZONE_OFFSET)/(60*60*1000))); System.out.println("DST_OFFSET: " + (calendar.get(Calendar.DST_OFFSET)/(60*60*1000))); System.out.println("Current Time, with hour reset to 3"); calendar.clear(Calendar.HOUR_OF_DAY); // so doesn't override calendar.set(Calendar.HOUR, 3); System.out.println("ERA: " + calendar.get(Calendar.ERA)); System.out.println("YEAR: " + calendar.get(Calendar.YEAR)); System.out.println("MONTH: " + calendar.get(Calendar.MONTH)); System.out.println("WEEK_OF_YEAR: " + calendar.get(Calendar.WEEK_OF_YEAR)); System.out.println("WEEK_OF_MONTH: " + calendar.get(Calendar.WEEK_OF_MONTH)); System.out.println("DATE: " + calendar.get(Calendar.DATE)); System.out.println("DAY_OF_MONTH: " + calendar.get(Calendar.DAY_OF_MONTH)); System.out.println("DAY_OF_YEAR: " + calendar.get(Calendar.DAY_OF_YEAR)); System.out.println("DAY_OF_WEEK: " + calendar.get(Calendar.DAY_OF_WEEK)); System.out.println("DAY_OF_WEEK_IN_MONTH: " + calendar.get(Calendar.DAY_OF_WEEK_IN_MONTH)); System.out.println("AM_PM: " + calendar.get(Calendar.AM_PM)); System.out.println("HOUR: " + calendar.get(Calendar.HOUR)); System.out.println("HOUR_OF_DAY: " + calendar.get(Calendar.HOUR_OF_DAY)); System.out.println("MINUTE: " + calendar.get(Calendar.MINUTE)); System.out.println("SECOND: " + calendar.get(Calendar.SECOND)); System.out.println("MILLISECOND: " + calendar.get(Calendar.MILLISECOND)); System.out.println("ZONE_OFFSET: " + (calendar.get(Calendar.ZONE_OFFSET)/(60*60*1000))); // in hours System.out.println("DST_OFFSET: " + (calendar.get(Calendar.DST_OFFSET)/(60*60*1000))); // in hours
GregorianCalendar usually should be instantiated using android.icu.util.Calendar#getInstance(ULocale)
passing in a ULocale
with the tag "@calendar=gregorian"
.
Summary
Constants | |
---|---|
static Int |
Value of the |
static Int |
Value of the |
Inherited constants | |
---|---|
Public constructors | |
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Constructs a default GregorianCalendar using the current time in the default time zone with the default |
|
GregorianCalendar(zone: TimeZone!) Constructs a GregorianCalendar based on the current time in the given time zone with the default |
|
GregorianCalendar(aLocale: Locale!) Constructs a GregorianCalendar based on the current time in the default time zone with the given locale. |
|
GregorianCalendar(locale: ULocale!) [icu] Constructs a GregorianCalendar based on the current time in the default time zone with the given locale. |
|
GregorianCalendar(zone: TimeZone!, aLocale: Locale!) [icu] Constructs a GregorianCalendar based on the current time in the given time zone with the given locale. |
|
GregorianCalendar(zone: TimeZone!, locale: ULocale!) Constructs a GregorianCalendar based on the current time in the given time zone with the given locale. |
|
GregorianCalendar(year: Int, month: Int, date: Int) Constructs a GregorianCalendar with the given date set in the default time zone with the default |
|
Constructs a GregorianCalendar with the given date and time set for the default time zone with the default |
|
Constructs a GregorianCalendar with the given date and time set for the default time zone with the default |
Public methods | |
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open Int |
getActualMaximum(field: Int) Return the maximum value that this field could have, given the current date. |
open Int |
getActualMinimum(field: Int) Return the minimum value that this field could have, given the current date. |
Date! |
Gets the Gregorian Calendar change date. |
open String! |
getType() [icu] Returns the calendar type name string for this Calendar object. |
open Int |
hashCode() Override hashCode. |
open Boolean |
isEquivalentTo(other: Calendar!) Returns true if the given Calendar object is equivalent to this one. |
open Boolean |
isLeapYear(year: Int) Determines if the given year is a leap year. |
open Unit |
Roll a field by a signed amount. |
open Unit |
setGregorianChange(date: Date!) Sets the GregorianCalendar change date. |
Protected methods | |
---|---|
open Unit |
handleComputeFields(julianDay: Int) Override Calendar to compute several fields specific to the hybrid Gregorian-Julian calendar system. |
open Int |
handleComputeJulianDay(bestField: Int) |
open Int |
handleComputeMonthStart(eyear: Int, month: Int, useMonth: Boolean) Return JD of start of given month/year |
open Int | |
open Int |
handleGetLimit(field: Int, limitType: Int) |
open Int |
handleGetMonthLength(extendedYear: Int, month: Int) |
open Int |
handleGetYearLength(eyear: Int) |
Inherited functions | |
---|---|
Properties | |
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Boolean |
Used by handleComputeJulianDay() and handleComputeMonthStart(). |
Boolean |
Used by handleComputeJulianDay() and handleComputeMonthStart(). |
Inherited properties | |
---|---|
Constants
AD
static val AD: Int
Value of the ERA
field indicating the common era (Anno Domini), also known as CE. The sequence of years at the transition from BC
to AD
is ..., 2 BC, 1 BC, 1 AD, 2 AD,...
Value: 1
See Also
BC
static val BC: Int
Value of the ERA
field indicating the period before the common era (before Christ), also known as BCE. The sequence of years at the transition from BC
to AD
is ..., 2 BC, 1 BC, 1 AD, 2 AD,...
Value: 0
See Also
Public constructors
GregorianCalendar
GregorianCalendar()
Constructs a default GregorianCalendar using the current time in the default time zone with the default FORMAT
locale.
GregorianCalendar
GregorianCalendar(zone: TimeZone!)
Constructs a GregorianCalendar based on the current time in the given time zone with the default FORMAT
locale.
Parameters | |
---|---|
zone |
TimeZone!: the given time zone. |
GregorianCalendar
GregorianCalendar(aLocale: Locale!)
Constructs a GregorianCalendar based on the current time in the default time zone with the given locale.
Parameters | |
---|---|
aLocale |
Locale!: the given locale. |
GregorianCalendar
GregorianCalendar(locale: ULocale!)
[icu] Constructs a GregorianCalendar based on the current time in the default time zone with the given locale.
Parameters | |
---|---|
locale |
ULocale!: the given ulocale. |
GregorianCalendar
GregorianCalendar(
zone: TimeZone!,
aLocale: Locale!)
[icu] Constructs a GregorianCalendar based on the current time in the given time zone with the given locale.
Parameters | |
---|---|
zone |
TimeZone!: the given time zone. |
aLocale |
Locale!: the given locale. |
GregorianCalendar
GregorianCalendar(
zone: TimeZone!,
locale: ULocale!)
Constructs a GregorianCalendar based on the current time in the given time zone with the given locale.
Parameters | |
---|---|
zone |
TimeZone!: the given time zone. |
locale |
ULocale!: the given ulocale. |
GregorianCalendar
GregorianCalendar(
year: Int,
month: Int,
date: Int)
Constructs a GregorianCalendar with the given date set in the default time zone with the default FORMAT
locale.
Parameters | |
---|---|
year |
Int: the value used to set the YEAR time field in the calendar. |
month |
Int: the value used to set the MONTH time field in the calendar. Month value is 0-based. e.g., 0 for January. |
date |
Int: the value used to set the DATE time field in the calendar. |
GregorianCalendar
GregorianCalendar(
year: Int,
month: Int,
date: Int,
hour: Int,
minute: Int)
Constructs a GregorianCalendar with the given date and time set for the default time zone with the default FORMAT
locale.
Parameters | |
---|---|
year |
Int: the value used to set the YEAR time field in the calendar. |
month |
Int: the value used to set the MONTH time field in the calendar. Month value is 0-based. e.g., 0 for January. |
date |
Int: the value used to set the DATE time field in the calendar. |
hour |
Int: the value used to set the HOUR_OF_DAY time field in the calendar. |
minute |
Int: the value used to set the MINUTE time field in the calendar. |
GregorianCalendar
GregorianCalendar(
year: Int,
month: Int,
date: Int,
hour: Int,
minute: Int,
second: Int)
Constructs a GregorianCalendar with the given date and time set for the default time zone with the default FORMAT
locale.
Parameters | |
---|---|
year |
Int: the value used to set the YEAR time field in the calendar. |
month |
Int: the value used to set the MONTH time field in the calendar. Month value is 0-based. e.g., 0 for January. |
date |
Int: the value used to set the DATE time field in the calendar. |
hour |
Int: the value used to set the HOUR_OF_DAY time field in the calendar. |
minute |
Int: the value used to set the MINUTE time field in the calendar. |
second |
Int: the value used to set the SECOND time field in the calendar. |
Public methods
getActualMaximum
open fun getActualMaximum(field: Int): Int
Return the maximum value that this field could have, given the current date. For example, with the date "Feb 3, 1997" and the DAY_OF_MONTH field, the actual maximum would be 28; for "Feb 3, 1996" it s 29. Similarly for a Hebrew calendar, for some years the actual maximum for MONTH is 12, and for others 13.
Parameters | |
---|---|
field |
Int: the field whose maximum is desired |
Return | |
---|---|
Int |
the maximum of the given field for the current date of this calendar |
getActualMinimum
open fun getActualMinimum(field: Int): Int
Return the minimum value that this field could have, given the current date. For the Gregorian calendar, this is the same as getMinimum() and getGreatestMinimum().
Parameters | |
---|---|
field |
Int: the field whose actual minimum value is desired. |
Return | |
---|---|
Int |
the minimum of the given field for the current date of this calendar |
getGregorianChange
fun getGregorianChange(): Date!
Gets the Gregorian Calendar change date. This is the point when the switch from Julian dates to Gregorian dates occurred. Default is October 15, 1582. Previous to this, dates will be in the Julian calendar.
Return | |
---|---|
Date! |
the Gregorian cutover date for this calendar. |
getType
open fun getType(): String!
[icu] Returns the calendar type name string for this Calendar object. The returned string is the legacy ICU calendar attribute value, for example, "gregorian" or "japanese".
See type="old type name" for the calendar attribute of locale IDs at http://www.unicode.org/reports/tr35/#Key_Type_Definitions
Return | |
---|---|
String! |
legacy calendar type name string |
hashCode
open fun hashCode(): Int
Override hashCode. Generates the hash code for the GregorianCalendar object
Return | |
---|---|
Int |
a hash code value for this object. |
isEquivalentTo
open fun isEquivalentTo(other: Calendar!): Boolean
Returns true if the given Calendar object is equivalent to this one. Calendar override.
Parameters | |
---|---|
other |
Calendar!: the Calendar to be compared with this Calendar |
isLeapYear
open fun isLeapYear(year: Int): Boolean
Determines if the given year is a leap year. Returns true if the given year is a leap year.
Parameters | |
---|---|
year |
Int: the given year. |
Return | |
---|---|
Boolean |
true if the given year is a leap year; false otherwise. |
roll
open fun roll(
field: Int,
amount: Int
): Unit
Roll a field by a signed amount.
Parameters | |
---|---|
field |
Int: the calendar field to roll. |
amount |
Int: the amount by which the field should be rolled. |
setGregorianChange
open fun setGregorianChange(date: Date!): Unit
Sets the GregorianCalendar change date. This is the point when the switch from Julian dates to Gregorian dates occurred. Default is October 15, 1582. Previous to this, dates will be in the Julian calendar.
To obtain a pure Julian calendar, set the change date to Date(Long.MAX_VALUE)
. To obtain a pure Gregorian calendar, set the change date to Date(Long.MIN_VALUE)
.
Parameters | |
---|---|
date |
Date!: the given Gregorian cutover date. |
Protected methods
handleComputeFields
protected open fun handleComputeFields(julianDay: Int): Unit
Override Calendar to compute several fields specific to the hybrid Gregorian-Julian calendar system. These are:
- ERA
- YEAR
- MONTH
- DAY_OF_MONTH
- DAY_OF_YEAR
- EXTENDED_YEAR
handleComputeJulianDay
protected open fun handleComputeJulianDay(bestField: Int): Int
handleComputeMonthStart
protected open fun handleComputeMonthStart(
eyear: Int,
month: Int,
useMonth: Boolean
): Int
Return JD of start of given month/year
Parameters | |
---|---|
eyear |
Int: the extended year |
month |
Int: the zero-based month, or 0 if useMonth is false |
useMonth |
Boolean: if false, compute the day before the first day of the given year, otherwise, compute the day before the first day of the given month |
Return | |
---|---|
Int |
the Julian day number of the day before the first day of the given month and year |
handleGetExtendedYear
protected open fun handleGetExtendedYear(): Int
Return | |
---|---|
Int |
the extended year |
handleGetLimit
protected open fun handleGetLimit(
field: Int,
limitType: Int
): Int
Parameters | |
---|---|
field |
Int: one of the above field numbers |
limitType |
Int: one of MINIMUM , GREATEST_MINIMUM , LEAST_MAXIMUM , or MAXIMUM |
handleGetMonthLength
protected open fun handleGetMonthLength(
extendedYear: Int,
month: Int
): Int
Properties
invertGregorian
protected var invertGregorian: Boolean
Used by handleComputeJulianDay() and handleComputeMonthStart().
isGregorian
protected var isGregorian: Boolean
Used by handleComputeJulianDay() and handleComputeMonthStart().