Added in API level 1

GregorianCalendar

open class GregorianCalendar : Calendar

kotlin.Any
↳	java.util.Calendar
	↳	java.util.GregorianCalendar

GregorianCalendar is a concrete subclass of Calendar and provides the standard calendar system used by most of the world.

GregorianCalendar is a hybrid calendar that supports both the Julian and Gregorian calendar systems with the support of a single discontinuity, which corresponds by default to the Gregorian date when 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 (Julian) was thus followed by October 15, 1582 (Gregorian). 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.

Week Of Year and Week Year

Values calculated for the WEEK_OF_YEAR field range from 1 to 53. The first week of a calendar 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 (exclusive) are numbered sequentially from 2 to 52 or 53 (except for year(s) involved in the Julian-Gregorian transition).

The getFirstDayOfWeek() and getMinimalDaysInFirstWeek() values are initialized using locale-dependent resources when constructing a GregorianCalendar. The week determination is compatible with the ISO 8601 standard when getFirstDayOfWeek() is MONDAY and getMinimalDaysInFirstWeek() is 4, which values are used in locales where the standard is preferred. These values can explicitly be set by calling setFirstDayOfWeek() and setMinimalDaysInFirstWeek().

A week year is in sync with a WEEK_OF_YEAR cycle. All weeks between the first and last weeks (inclusive) have the same week year value. Therefore, the first and last days of a week year may have different calendar year values.

For example, January 1, 1998 is a Thursday. If getFirstDayOfWeek() is MONDAY and getMinimalDaysInFirstWeek() is 4 (ISO 8601 standard compatible setting), then week 1 of 1998 starts on December 29, 1997, and ends on January 4, 1998. The week year is 1998 for the last three days of calendar year 1997. 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 and their week year is 1997.

Week Of Month

Values calculated for the WEEK_OF_MONTH field range from 0 to 6. 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.

Default Fields Values

The clear method sets calendar field(s) undefined. GregorianCalendar uses the following default value for each calendar field if its value is undefined.

GregorianCalendar default field values

Field	Default Value
ERA	AD
YEAR	1970
MONTH	JANUARY
DAY_OF_MONTH	1
DAY_OF_WEEK	the first day of week
WEEK_OF_MONTH	0
DAY_OF_WEEK_IN_MONTH	1
AM_PM	AM
HOUR, HOUR_OF_DAY, MINUTE, SECOND, MILLISECOND	0

Default values are not applicable for the fields not listed above.

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 Saving Time
  pdt.setStartRule(Calendar.APRIL, 1, Calendar.SUNDAY, 2 * 60 * 60 * 1000);
  pdt.setEndRule(Calendar.OCTOBER, -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
  

Summary

Constants
static Int	AD Value of the ERA field indicating the common era (Anno Domini), also known as CE.
static Int	BC Value of the ERA field indicating the period before the common era (before Christ), also known as BCE.

Inherited constants

From class Calendar Int ALL_STYLES A style specifier for getDisplayNames indicating names in all styles, such as "January" and "Jan". Int AM Value of the AM_PM field indicating the period of the day from midnight to just before noon. Int AM_PM Field number for get and set indicating whether the HOUR is before or after noon. E.g., at 10:04:15.250 PM the AM_PM is PM. Int APRIL Value of the MONTH field indicating the fourth month of the year in the Gregorian and Julian calendars. Int AUGUST Value of the MONTH field indicating the eighth month of the year in the Gregorian and Julian calendars. Int DATE Field number for get and set indicating the day of the month. This is a synonym for DAY_OF_MONTH. The first day of the month has value 1. Int DAY_OF_MONTH Field number for get and set indicating the day of the month. This is a synonym for DATE. The first day of the month has value 1. Int DAY_OF_WEEK Field number for get and set indicating the day of the week. This field takes values SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, and SATURDAY. Int DAY_OF_WEEK_IN_MONTH Field number for get and set indicating the ordinal number of the day of the week within the current month. Together with the DAY_OF_WEEK field, this uniquely specifies a day within a month. Unlike WEEK_OF_MONTH and WEEK_OF_YEAR, this field's value does not depend on getFirstDayOfWeek() or getMinimalDaysInFirstWeek(). DAY_OF_MONTH 1 through 7 always correspond to DAY_OF_WEEK_IN_MONTH 1; 8 through 14 correspond to DAY_OF_WEEK_IN_MONTH 2, and so on. DAY_OF_WEEK_IN_MONTH 0 indicates the week before DAY_OF_WEEK_IN_MONTH 1. Negative values count back from the end of the month, so the last Sunday of a month is specified as DAY_OF_WEEK = SUNDAY, DAY_OF_WEEK_IN_MONTH = -1. Because negative values count backward they will usually be aligned differently within the month than positive values. For example, if a month has 31 days, DAY_OF_WEEK_IN_MONTH -1 will overlap DAY_OF_WEEK_IN_MONTH 5 and the end of 4. Int DAY_OF_YEAR Field number for get and set indicating the day number within the current year. The first day of the year has value 1. Int DECEMBER Value of the MONTH field indicating the twelfth month of the year in the Gregorian and Julian calendars. Int DST_OFFSET Field number for get and set indicating the daylight saving offset in milliseconds. This field reflects the correct daylight saving offset value of the time zone of this Calendar if the TimeZone implementation subclass supports historical Daylight Saving Time schedule changes. Int ERA Field number for get and set indicating the era, e.g., AD or BC in the Julian calendar. This is a calendar-specific value; see subclass documentation. Int FEBRUARY Value of the MONTH field indicating the second month of the year in the Gregorian and Julian calendars. Int FIELD_COUNT The number of distinct fields recognized by get and set. Field numbers range from 0..FIELD_COUNT-1. Int FRIDAY Value of the DAY_OF_WEEK field indicating Friday. Int HOUR Field number for get and set indicating the hour of the morning or afternoon. HOUR is used for the 12-hour clock (0 - 11). Noon and midnight are represented by 0, not by 12. E.g., at 10:04:15.250 PM the HOUR is 10. Int HOUR_OF_DAY Field number for get and set indicating the hour of the day. HOUR_OF_DAY is used for the 24-hour clock. E.g., at 10:04:15.250 PM the HOUR_OF_DAY is 22. Int JANUARY Value of the MONTH field indicating the first month of the year in the Gregorian and Julian calendars. Int JULY Value of the MONTH field indicating the seventh month of the year in the Gregorian and Julian calendars. Int JUNE Value of the MONTH field indicating the sixth month of the year in the Gregorian and Julian calendars. Int LONG A style specifier for getDisplayName and getDisplayNames equivalent to LONG_FORMAT. Int LONG_FORMAT A style specifier for getDisplayName and getDisplayNames indicating a long name used for format. Int LONG_STANDALONE A style specifier for getDisplayName and getDisplayNames indicating a long name used independently, such as a month name as calendar headers. Int MARCH Value of the MONTH field indicating the third month of the year in the Gregorian and Julian calendars. Int MAY Value of the MONTH field indicating the fifth month of the year in the Gregorian and Julian calendars. Int MILLISECOND Field number for get and set indicating the millisecond within the second. E.g., at 10:04:15.250 PM the MILLISECOND is 250. Int MINUTE Field number for get and set indicating the minute within the hour. E.g., at 10:04:15.250 PM the MINUTE is 4. Int MONDAY Value of the DAY_OF_WEEK field indicating Monday. Int MONTH Field number for get and set indicating the month. This is a calendar-specific value. The first month of the year in the Gregorian and Julian calendars is JANUARY which is 0; the last depends on the number of months in a year. Int NARROW_FORMAT A style specifier for getDisplayName and getDisplayNames indicating a narrow name used for format. Narrow names are typically single character strings, such as "M" for Monday. Int NARROW_STANDALONE A style specifier for getDisplayName and getDisplayNames indicating a narrow name independently. Narrow names are typically single character strings, such as "M" for Monday. Int NOVEMBER Value of the MONTH field indicating the eleventh month of the year in the Gregorian and Julian calendars. Int OCTOBER Value of the MONTH field indicating the tenth month of the year in the Gregorian and Julian calendars. Int PM Value of the AM_PM field indicating the period of the day from noon to just before midnight. Int SATURDAY Value of the DAY_OF_WEEK field indicating Saturday. Int SECOND Field number for get and set indicating the second within the minute. E.g., at 10:04:15.250 PM the SECOND is 15. Int SEPTEMBER Value of the MONTH field indicating the ninth month of the year in the Gregorian and Julian calendars. Int SHORT A style specifier for getDisplayName and getDisplayNames equivalent to SHORT_FORMAT. Int SHORT_FORMAT A style specifier for getDisplayName and getDisplayNames indicating a short name used for format. Int SHORT_STANDALONE A style specifier for getDisplayName and getDisplayNames indicating a short name used independently, such as a month abbreviation as calendar headers. Int SUNDAY Value of the DAY_OF_WEEK field indicating Sunday. Int THURSDAY Value of the DAY_OF_WEEK field indicating Thursday. Int TUESDAY Value of the DAY_OF_WEEK field indicating Tuesday. Int UNDECIMBER Value of the MONTH field indicating the thirteenth month of the year. Although GregorianCalendar does not use this value, lunar calendars do. Int WEDNESDAY Value of the DAY_OF_WEEK field indicating Wednesday. Int WEEK_OF_MONTH Field number for get and set indicating the week number within the current month. The first week of the month, as defined by getFirstDayOfWeek() and getMinimalDaysInFirstWeek(), has value 1. Subclasses define the value of WEEK_OF_MONTH for days before the first week of the month. Int WEEK_OF_YEAR Field number for get and set indicating the week number within the current year. The first week of the year, as defined by getFirstDayOfWeek() and getMinimalDaysInFirstWeek(), has value 1. Subclasses define the value of WEEK_OF_YEAR for days before the first week of the year. Int YEAR Field number for get and set indicating the year. This is a calendar-specific value; see subclass documentation. Int ZONE_OFFSET Field number for get and set indicating the raw offset from GMT in milliseconds. This field reflects the correct GMT offset value of the time zone of this Calendar if the TimeZone implementation subclass supports historical GMT offset changes.

Public constructors
GregorianCalendar() Constructs a default GregorianCalendar using the current time in the default time zone with the default FORMAT locale.
GregorianCalendar(year: Int, month: Int, dayOfMonth: Int) Constructs a GregorianCalendar with the given date set in the default time zone with the default locale.
GregorianCalendar(year: Int, month: Int, dayOfMonth: Int, hourOfDay: Int, minute: Int) Constructs a GregorianCalendar with the given date and time set for the default time zone with the default locale.
GregorianCalendar(year: Int, month: Int, dayOfMonth: Int, hourOfDay: Int, minute: Int, second: Int) Constructs a GregorianCalendar with the given date and time set for the default time zone with the default locale.
GregorianCalendar(aLocale: Locale!) Constructs a GregorianCalendar based on the current time in the default time zone with the given locale.
GregorianCalendar(zone: TimeZone!) Constructs a GregorianCalendar based on the current time in the given time zone with the default FORMAT locale.
GregorianCalendar(zone: TimeZone!, aLocale: Locale!) Constructs a GregorianCalendar based on the current time in the given time zone with the given locale.

Public methods
open Unit	add(field: Int, amount: Int) Adds the specified (signed) amount of time to the given calendar field, based on the calendar's rules.
open Any	clone()
open Boolean	equals(other: Any?) Compares this GregorianCalendar to the specified Object.
open static GregorianCalendar!	from(zdt: ZonedDateTime!) Obtains an instance of GregorianCalendar with the default locale from a ZonedDateTime object.
open Int	getActualMaximum(field: Int) Returns the maximum value that this calendar field could have, taking into consideration the given time value and the current values of the getFirstDayOfWeek, getMinimalDaysInFirstWeek, getGregorianChange and getTimeZone methods.
open Int	getActualMinimum(field: Int) Returns the minimum value that this calendar field could have, taking into consideration the given time value and the current values of the getFirstDayOfWeek, getMinimalDaysInFirstWeek, getGregorianChange and getTimeZone methods.
open String	getCalendarType() Returns "gregory" as the calendar type.
open Int	getGreatestMinimum(field: Int) Returns the highest minimum value for the given calendar field of this GregorianCalendar instance.
Date!	getGregorianChange() Gets the Gregorian Calendar change date.
open Int	getLeastMaximum(field: Int) Returns the lowest maximum value for the given calendar field of this GregorianCalendar instance.
open Int	getMaximum(field: Int) Returns the maximum value for the given calendar field of this GregorianCalendar instance.
open Int	getMinimum(field: Int) Returns the minimum value for the given calendar field of this GregorianCalendar instance.
open TimeZone	getTimeZone()
open Int	getWeekYear() Returns the week year represented by this GregorianCalendar.
open Int	getWeeksInWeekYear() Returns the number of weeks in the week year represented by this GregorianCalendar.
open Int	hashCode() Generates the hash code for this GregorianCalendar object.
open Boolean	isLeapYear(year: Int) Determines if the given year is a leap year.
Boolean	isWeekDateSupported() Returns true indicating this GregorianCalendar supports week dates.
open Unit	roll(field: Int, up: Boolean) Adds or subtracts (up/down) a single unit of time on the given time field without changing larger fields.
open Unit	roll(field: Int, amount: Int) Adds a signed amount to the specified calendar field without changing larger fields.
open Unit	setGregorianChange(date: Date!) Sets the GregorianCalendar change date.
open Unit	setTimeZone(zone: TimeZone)
open Unit	setWeekDate(weekYear: Int, weekOfYear: Int, dayOfWeek: Int) Sets this GregorianCalendar to the date given by the date specifiers - weekYear, weekOfYear, and dayOfWeek.
open ZonedDateTime!	toZonedDateTime() Converts this object to a ZonedDateTime that represents the same point on the time-line as this GregorianCalendar.

Protected methods
open Unit	computeFields() Converts the time value (millisecond offset from the Epoch) to calendar field values.
open Unit	computeTime() Converts calendar field values to the time value (millisecond offset from the Epoch).

Inherited functions

From class Calendar Boolean after(when: Any?) Returns whether this Calendar represents a time after the time represented by the specified Object. This method is equivalent to: <code>compareTo(when) &gt; 0 </code> if and only if when is a Calendar instance. Otherwise, the method returns false. Boolean before(when: Any?) Returns whether this Calendar represents a time before the time represented by the specified Object. This method is equivalent to: <code>compareTo(when) &lt; 0 </code> if and only if when is a Calendar instance. Otherwise, the method returns false. Unit clear() Sets all the calendar field values and the time value (millisecond offset from the Epoch) of this Calendar undefined. This means that isSet() will return false for all the calendar fields, and the date and time calculations will treat the fields as if they had never been set. A Calendar implementation class may use its specific default field values for date/time calculations. For example, GregorianCalendar uses 1970 if the YEAR field value is undefined. Unit clear(field: Int) Sets the given calendar field value and the time value (millisecond offset from the Epoch) of this Calendar undefined. This means that isSet(field) will return false, and the date and time calculations will treat the field as if it had never been set. A Calendar implementation class may use the field's specific default value for date and time calculations. The HOUR_OF_DAY, HOUR and AM_PM fields are handled independently and the the resolution rule for the time of day is applied. Clearing one of the fields doesn't reset the hour of day value of this Calendar. Use set(Calendar.HOUR_OF_DAY, 0) to reset the hour value. Int compareTo(other: Calendar) Compares the time values (millisecond offsets from the Epoch) represented by two Calendar objects. Unit complete() Fills in any unset fields in the calendar fields. First, the computeTime() method is called if the time value (millisecond offset from the Epoch) has not been calculated from calendar field values. Then, the computeFields() method is called to calculate all calendar field values. Int get(field: Int) Returns the value of the given calendar field. In lenient mode, all calendar fields are normalized. In non-lenient mode, all calendar fields are validated and this method throws an exception if any calendar fields have out-of-range values. The normalization and validation are handled by the complete() method, which process is calendar system dependent. MutableSet<String!> getAvailableCalendarTypes() Returns an unmodifiable Set containing all calendar types supported by Calendar in the runtime environment. The available calendar types can be used for the Unicode locale extensions. The Set returned contains at least "gregory". The calendar types don't include aliases, such as "gregorian" for "gregory". Array<Locale!> getAvailableLocales() Returns an array of all locales for which the getInstance methods of this class can return localized instances. The array returned must contain at least a Locale instance equal to Locale.US. String? getDisplayName(field: Int, style: Int, locale: Locale) Returns the string representation of the calendar field value in the given style and locale. If no string representation is applicable, null is returned. This method calls get(field) to get the calendar field value if the string representation is applicable to the given calendar field. For example, if this Calendar is a GregorianCalendar and its date is 2005-01-01, then the string representation of the MONTH field would be "January" in the long style in an English locale or "Jan" in the short style. However, no string representation would be available for the DAY_OF_MONTH field, and this method would return null. The default implementation supports the calendar fields for which a DateFormatSymbols has names in the given locale. MutableMap<String!, Int!>? getDisplayNames(field: Int, style: Int, locale: Locale) Returns a Map containing all names of the calendar field in the given style and locale and their corresponding field values. For example, if this Calendar is a GregorianCalendar, the returned map would contain "Jan" to JANUARY, "Feb" to FEBRUARY, and so on, in the short style in an English locale. Narrow names may not be unique due to use of single characters, such as "S" for Sunday and Saturday. In that case narrow names are not included in the returned Map. The values of other calendar fields may be taken into account to determine a set of display names. For example, if this Calendar is a lunisolar calendar system and the year value given by the YEAR field has a leap month, this method would return month names containing the leap month name, and month names are mapped to their values specific for the year. The default implementation supports display names contained in a DateFormatSymbols. For example, if field is MONTH and style is ALL_STYLES, this method returns a Map containing all strings returned by DateFormatSymbols.getShortMonths() and DateFormatSymbols.getMonths(). Int getFirstDayOfWeek() Gets what the first day of the week is; e.g., SUNDAY in the U.S., MONDAY in France. Calendar getInstance() Gets a calendar using the default time zone and locale. The Calendar returned is based on the current time in the default time zone with the default FORMAT locale. Since Android 13, if the locale contains the time zone with "tz" Unicode extension, that time zone is used instead. Calendar getInstance(aLocale: Locale) Gets a calendar using the default time zone and specified locale. The Calendar returned is based on the current time in the default time zone with the given locale. Since Android 13, if the locale contains the time zone with "tz" Unicode extension, that time zone is used instead. Calendar getInstance(zone: TimeZone) Gets a calendar using the specified time zone and default locale. The Calendar returned is based on the current time in the given time zone with the default FORMAT locale. Calendar getInstance(zone: TimeZone, aLocale: Locale) Gets a calendar with the specified time zone and locale. The Calendar returned is based on the current time in the given time zone with the given locale. Int getMinimalDaysInFirstWeek() Gets what the minimal days required in the first week of the year are; e.g., if the first week is defined as one that contains the first day of the first month of a year, this method returns 1. If the minimal days required must be a full week, this method returns 7. Date getTime() Returns a Date object representing this Calendar's time value (millisecond offset from the Epoch"). Long getTimeInMillis() Returns this Calendar's time value in milliseconds. Int internalGet(field: Int) Returns the value of the given calendar field. This method does not involve normalization or validation of the field value. Boolean isLenient() Tells whether date/time interpretation is to be lenient. Boolean isSet(field: Int) Determines if the given calendar field has a value set, including cases that the value has been set by internal fields calculations triggered by a get method call. Unit set(field: Int, value: Int) Sets the given calendar field to the given value. The value is not interpreted by this method regardless of the leniency mode. Unit set(year: Int, month: Int, date: Int) Sets the values for the calendar fields YEAR, MONTH, and DAY_OF_MONTH. Previous values of other calendar fields are retained. If this is not desired, call clear() first. Unit set(year: Int, month: Int, date: Int, hourOfDay: Int, minute: Int) Sets the values for the calendar fields YEAR, MONTH, DAY_OF_MONTH, HOUR_OF_DAY, and MINUTE. Previous values of other fields are retained. If this is not desired, call clear() first. Unit set(year: Int, month: Int, date: Int, hourOfDay: Int, minute: Int, second: Int) Sets the values for the fields YEAR, MONTH, DAY_OF_MONTH, HOUR_OF_DAY, MINUTE, and SECOND. Previous values of other fields are retained. If this is not desired, call clear() first. Unit setFirstDayOfWeek(value: Int) Sets what the first day of the week is; e.g., SUNDAY in the U.S., MONDAY in France. Unit setLenient(lenient: Boolean) Specifies whether or not date/time interpretation is to be lenient. With lenient interpretation, a date such as "February 942, 1996" will be treated as being equivalent to the 941st day after February 1, 1996. With strict (non-lenient) interpretation, such dates will cause an exception to be thrown. The default is lenient. Unit setMinimalDaysInFirstWeek(value: Int) Sets what the minimal days required in the first week of the year are; For example, if the first week is defined as one that contains the first day of the first month of a year, call this method with value 1. If it must be a full week, use value 7. Unit setTime(date: Date) Sets this Calendar's time with the given Date. Note: Calling setTime() with Date(Long.MAX_VALUE) or Date(Long.MIN_VALUE) may yield incorrect field values from get(). Unit setTimeInMillis(millis: Long) Sets this Calendar's current time from the given long value. Instant toInstant() Converts this object to an Instant. The conversion creates an Instant that represents the same point on the time-line as this Calendar. String toString() Return a string representation of this calendar. This method is intended to be used only for debugging purposes, and the format of the returned string may vary between implementations. The returned string may be empty but may not be null.

Inherited properties

From class Calendar Boolean areFieldsSet True if fields[] are in sync with the currently set time. If false, then the next attempt to get the value of a field will force a recomputation of all fields from the current value of time. IntArray fields The calendar field values for the currently set time for this calendar. This is an array of FIELD_COUNT integers, with index values ERA through DST_OFFSET. BooleanArray isSet The flags which tell if a specified calendar field for the calendar is set. A new object has no fields set. After the first call to a method which generates the fields, they all remain set after that. This is an array of FIELD_COUNT booleans, with index values ERA through DST_OFFSET. Boolean isTimeSet True if then the value of time is valid. The time is made invalid by a change to an item of field[]. Long time The currently set time for this calendar, expressed in milliseconds after January 1, 1970, 0:00:00 GMT.

Constants

AD

Added in API level 1

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

• #ERA

BC

Added in API level 1

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

• #ERA

Public constructors

GregorianCalendar

Added in API level 1

GregorianCalendar()

Constructs a default GregorianCalendar using the current time in the default time zone with the default FORMAT locale.

GregorianCalendar

Added in API level 1

GregorianCalendar(
    year: Int, 
    month: Int, 
    dayOfMonth: Int)

Constructs a GregorianCalendar with the given date set in the default time zone with the default locale.

Parameters
year	Int: the value used to set the YEAR calendar field in the calendar.
month	Int: the value used to set the MONTH calendar field in the calendar. Month value is 0-based. e.g., 0 for January.
dayOfMonth	Int: the value used to set the DAY_OF_MONTH calendar field in the calendar.

GregorianCalendar

Added in API level 1

GregorianCalendar(
    year: Int, 
    month: Int, 
    dayOfMonth: Int, 
    hourOfDay: Int, 
    minute: Int)

Constructs a GregorianCalendar with the given date and time set for the default time zone with the default locale.

Parameters
year	Int: the value used to set the YEAR calendar field in the calendar.
month	Int: the value used to set the MONTH calendar field in the calendar. Month value is 0-based. e.g., 0 for January.
dayOfMonth	Int: the value used to set the DAY_OF_MONTH calendar field in the calendar.
hourOfDay	Int: the value used to set the HOUR_OF_DAY calendar field in the calendar.
minute	Int: the value used to set the MINUTE calendar field in the calendar.

GregorianCalendar

Added in API level 1

GregorianCalendar(
    year: Int, 
    month: Int, 
    dayOfMonth: Int, 
    hourOfDay: Int, 
    minute: Int, 
    second: Int)

Constructs a GregorianCalendar with the given date and time set for the default time zone with the default locale.

Parameters
year	Int: the value used to set the YEAR calendar field in the calendar.
month	Int: the value used to set the MONTH calendar field in the calendar. Month value is 0-based. e.g., 0 for January.
dayOfMonth	Int: the value used to set the DAY_OF_MONTH calendar field in the calendar.
hourOfDay	Int: the value used to set the HOUR_OF_DAY calendar field in the calendar.
minute	Int: the value used to set the MINUTE calendar field in the calendar.
second	Int: the value used to set the SECOND calendar field in the calendar.

GregorianCalendar

Added in API level 1

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

Added in API level 1

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

Added in API level 1

GregorianCalendar(
    zone: TimeZone!, 
    aLocale: Locale!)

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.

Public methods

add

Added in API level 1

open fun add(
    field: Int, 
    amount: Int
): Unit

Adds the specified (signed) amount of time to the given calendar field, based on the calendar's rules.

Add rule 1. The value of field after the call minus the value of field before the call is amount, modulo any overflow that has occurred in field. Overflow occurs when a field value exceeds its range and, as a result, the next larger field is incremented or decremented and the field value is adjusted back into its range.

Add rule 2. If a smaller field is expected to be invariant, but it is impossible for it to be equal to its prior value because of changes in its minimum or maximum after field is changed, then its value is adjusted to be as close as possible to its expected value. A smaller field represents a smaller unit of time. HOUR is a smaller field than DAY_OF_MONTH. No adjustment is made to smaller fields that are not expected to be invariant. The calendar system determines what fields are expected to be invariant.

Parameters
field	Int: the calendar field.
amount	Int: the amount of date or time to be added to the field.

Exceptions
java.lang.IllegalArgumentException	if field is ZONE_OFFSET, DST_OFFSET, or unknown, or if any calendar fields have out-of-range values in non-lenient mode.

clone

Added in API level 1

open fun clone(): Any

Return
Any	a copy of this object.

Exceptions
java.lang.CloneNotSupportedException	if the object's class does not support the Cloneable interface. Subclasses that override the clone method can also throw this exception to indicate that an instance cannot be cloned.

equals

Added in API level 1

open fun equals(other: Any?): Boolean

Compares this GregorianCalendar to the specified Object. The result is true if and only if the argument is a GregorianCalendar object that represents the same time value (millisecond offset from the Epoch) under the same Calendar parameters and Gregorian change date as this object.

Parameters
obj	the object to compare with.

Return
Boolean	true if this object is equal to obj; false otherwise.

See Also

• java.util.Calendar#compareTo(Calendar)

from

Added in API level 26

open static fun from(zdt: ZonedDateTime!): GregorianCalendar!

Obtains an instance of GregorianCalendar with the default locale from a ZonedDateTime object.

Since ZonedDateTime does not support a Julian-Gregorian cutover date and uses ISO calendar system, the return GregorianCalendar is a pure Gregorian calendar and uses ISO 8601 standard for week definitions, which has MONDAY as the FirstDayOfWeek and 4 as the value of the MinimalDaysInFirstWeek.

ZoneDateTime can store points on the time-line further in the future and further in the past than GregorianCalendar. In this scenario, this method will throw an IllegalArgumentException exception.

Parameters
zdt	ZonedDateTime!: the zoned date-time object to convert

Return
GregorianCalendar!	the gregorian calendar representing the same point on the time-line as the zoned date-time provided

Exceptions
java.lang.NullPointerException	if zdt is null
java.lang.IllegalArgumentException	if the zoned date-time is too large to represent as a GregorianCalendar

getActualMaximum

Added in API level 1

open fun getActualMaximum(field: Int): Int

Returns the maximum value that this calendar field could have, taking into consideration the given time value and the current values of the getFirstDayOfWeek, getMinimalDaysInFirstWeek, getGregorianChange and getTimeZone methods. For example, if the date of this instance is February 1, 2004, the actual maximum value of the DAY_OF_MONTH field is 29 because 2004 is a leap year, and if the date of this instance is February 1, 2005, it's 28.

This method calculates the maximum value of WEEK_OF_YEAR based on the YEAR (calendar year) value, not the week year. Call getWeeksInWeekYear() to get the maximum value of WEEK_OF_YEAR in the week year of this GregorianCalendar.

Parameters
field	Int: the calendar field

Return
Int	the maximum of the given field for the time value of this GregorianCalendar

See Also

• #getMinimum(int)
• #getMaximum(int)
• #getGreatestMinimum(int)
• #getLeastMaximum(int)
• #getActualMinimum(int)

getActualMinimum

Added in API level 1

open fun getActualMinimum(field: Int): Int

Returns the minimum value that this calendar field could have, taking into consideration the given time value and the current values of the getFirstDayOfWeek, getMinimalDaysInFirstWeek, getGregorianChange and getTimeZone methods.

For example, if the Gregorian change date is January 10, 1970 and the date of this GregorianCalendar is January 20, 1970, the actual minimum value of the DAY_OF_MONTH field is 10 because the previous date of January 10, 1970 is December 27, 1996 (in the Julian calendar). Therefore, December 28, 1969 to January 9, 1970 don't exist.

Parameters
field	Int: the calendar field

Return
Int	the minimum of the given field for the time value of this GregorianCalendar

See Also

• #getMinimum(int)
• #getMaximum(int)
• #getGreatestMinimum(int)
• #getLeastMaximum(int)
• #getActualMaximum(int)

getCalendarType

Added in API level 26

open fun getCalendarType(): String

Returns "gregory" as the calendar type.

Return
String	"gregory"

getGreatestMinimum

Added in API level 1

open fun getGreatestMinimum(field: Int): Int

Returns the highest minimum value for the given calendar field of this GregorianCalendar instance. The highest minimum value is defined as the largest value returned by getActualMinimum(int) for any possible time value, taking into consideration the current values of the getFirstDayOfWeek, getMinimalDaysInFirstWeek, getGregorianChange and getTimeZone methods.

Parameters
field	Int: the calendar field.

Return
Int	the highest minimum value for the given calendar field.

See Also

• #getMinimum(int)
• #getMaximum(int)
• #getLeastMaximum(int)
• #getActualMinimum(int)
• #getActualMaximum(int)

getGregorianChange

Added in API level 1

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 (Gregorian). Previous to this, dates will be in the Julian calendar.

Return
Date!	the Gregorian cutover date for this GregorianCalendar object.

getLeastMaximum

Added in API level 1

open fun getLeastMaximum(field: Int): Int

Returns the lowest maximum value for the given calendar field of this GregorianCalendar instance. The lowest maximum value is defined as the smallest value returned by getActualMaximum(int) for any possible time value, taking into consideration the current values of the getFirstDayOfWeek, getMinimalDaysInFirstWeek, getGregorianChange and getTimeZone methods.

Parameters
field	Int: the calendar field

Return
Int	the lowest maximum value for the given calendar field.

See Also

• #getMinimum(int)
• #getMaximum(int)
• #getGreatestMinimum(int)
• #getActualMinimum(int)
• #getActualMaximum(int)

getMaximum

Added in API level 1

open fun getMaximum(field: Int): Int

Returns the maximum value for the given calendar field of this GregorianCalendar instance. The maximum value is defined as the largest value returned by the get method for any possible time value, taking into consideration the current values of the getFirstDayOfWeek, getMinimalDaysInFirstWeek, getGregorianChange and getTimeZone methods.

Parameters
field	Int: the calendar field.

Return
Int	the maximum value for the given calendar field.

See Also

• #getMinimum(int)
• #getGreatestMinimum(int)
• #getLeastMaximum(int)
• #getActualMinimum(int)
• #getActualMaximum(int)

getMinimum

Added in API level 1

open fun getMinimum(field: Int): Int

Returns the minimum value for the given calendar field of this GregorianCalendar instance. The minimum value is defined as the smallest value returned by the get method for any possible time value, taking into consideration the current values of the getFirstDayOfWeek, getMinimalDaysInFirstWeek, getGregorianChange and getTimeZone methods.

Parameters
field	Int: the calendar field.

Return
Int	the minimum value for the given calendar field.

See Also

• #getMaximum(int)
• #getGreatestMinimum(int)
• #getLeastMaximum(int)
• #getActualMinimum(int)
• #getActualMaximum(int)

getTimeZone

Added in API level 1

open fun getTimeZone(): TimeZone

Return
TimeZone	the time zone object associated with this calendar.

getWeekYear

Added in API level 24

open fun getWeekYear(): Int

Returns the week year represented by this GregorianCalendar. The dates in the weeks between 1 and the maximum week number of the week year have the same week year value that may be one year before or after the YEAR (calendar year) value.

This method calls Calendar.complete() before calculating the week year.

Return
Int	the week year represented by this GregorianCalendar. If the ERA value is BC, the year is represented by 0 or a negative number: BC 1 is 0, BC 2 is -1, BC 3 is -2, and so on.

Exceptions
java.lang.UnsupportedOperationException	if any week year numbering isn't supported in this Calendar.
java.lang.IllegalArgumentException	if any of the calendar fields is invalid in non-lenient mode.

See Also

• #isWeekDateSupported()
• #getWeeksInWeekYear()
• java.util.Calendar#getFirstDayOfWeek()
• java.util.Calendar#getMinimalDaysInFirstWeek()

getWeeksInWeekYear

Added in API level 24

open fun getWeeksInWeekYear(): Int

Returns the number of weeks in the week year represented by this GregorianCalendar.

For example, if this GregorianCalendar's date is December 31, 2008 with the ISO 8601 compatible setting, this method will return 53 for the period: December 29, 2008 to January 3, 2010 while getActualMaximum(WEEK_OF_YEAR) will return 52 for the period: December 31, 2007 to December 28, 2008.

Return
Int	the number of weeks in the week year.

Exceptions
java.lang.UnsupportedOperationException	if any week year numbering isn't supported in this Calendar.

See Also

• java.util.Calendar#WEEK_OF_YEAR
• #getWeekYear()
• #getActualMaximum(int)

hashCode

Added in API level 1

open fun hashCode(): Int

Generates the hash code for this GregorianCalendar object.

Return
Int	a hash code value for this object.

isLeapYear

Added in API level 1

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. To specify BC year numbers, 1 - year number must be given. For example, year BC 4 is specified as -3.

Parameters
year	Int: the given year.

Return
Boolean	true if the given year is a leap year; false otherwise.

isWeekDateSupported

Added in API level 24

fun isWeekDateSupported(): Boolean

Returns true indicating this GregorianCalendar supports week dates.

Return
Boolean	true (always)

See Also

• #getWeekYear()
• #setWeekDate(int,int,int)
• #getWeeksInWeekYear()

roll

Added in API level 1

open fun roll(
    field: Int, 
    up: Boolean
): Unit

Adds or subtracts (up/down) a single unit of time on the given time field without changing larger fields.

Example: Consider a GregorianCalendar originally set to December 31, 1999. Calling roll(Calendar.MONTH, true) sets the calendar to January 31, 1999. The YEAR field is unchanged because it is a larger field than MONTH.

Parameters
field	Int: the time field.
up	Boolean: indicates if the value of the specified calendar field is to be rolled up or rolled down. Use true if rolling up, false otherwise.

Exceptions
java.lang.IllegalArgumentException	if field is ZONE_OFFSET, DST_OFFSET, or unknown, or if any calendar fields have out-of-range values in non-lenient mode.

See Also

• #add(int,int)
• #set(int,int)

roll

Added in API level 1

open fun roll(
    field: Int, 
    amount: Int
): Unit

Adds a signed amount to the specified calendar field without changing larger fields. A negative roll amount means to subtract from field without changing larger fields. If the specified amount is 0, this method performs nothing.

This method calls complete() before adding the amount so that all the calendar fields are normalized. If there is any calendar field having an out-of-range value in non-lenient mode, then an IllegalArgumentException is thrown.

Example: Consider a GregorianCalendar originally set to August 31, 1999. Calling roll(Calendar.MONTH, 8) sets the calendar to April 30, 1999. Using a GregorianCalendar, the DAY_OF_MONTH field cannot be 31 in the month April. DAY_OF_MONTH is set to the closest possible value, 30. The YEAR field maintains the value of 1999 because it is a larger field than MONTH.

Example: Consider a GregorianCalendar originally set to Sunday June 6, 1999. Calling roll(Calendar.WEEK_OF_MONTH, -1) sets the calendar to Tuesday June 1, 1999, whereas calling add(Calendar.WEEK_OF_MONTH, -1) sets the calendar to Sunday May 30, 1999. This is because the roll rule imposes an additional constraint: The MONTH must not change when the WEEK_OF_MONTH is rolled. Taken together with add rule 1, the resultant date must be between Tuesday June 1 and Saturday June 5. According to add rule 2, the DAY_OF_WEEK, an invariant when changing the WEEK_OF_MONTH, is set to Tuesday, the closest possible value to Sunday (where Sunday is the first day of the week).

Parameters
field	Int: the calendar field.
amount	Int: the signed amount to add to field.

Exceptions
java.lang.IllegalArgumentException	if field is ZONE_OFFSET, DST_OFFSET, or unknown, or if any calendar fields have out-of-range values in non-lenient mode.

See Also

• #roll(int,boolean)
• #add(int,int)
• #set(int,int)

setGregorianChange

Added in API level 1

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 (Gregorian). 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.

setTimeZone

Added in API level 1

open fun setTimeZone(zone: TimeZone): Unit

Parameters
value	the given time zone.

setWeekDate

Added in API level 24

open fun setWeekDate(
    weekYear: Int, 
    weekOfYear: Int, 
    dayOfWeek: Int
): Unit

Sets this GregorianCalendar to the date given by the date specifiers - weekYear, weekOfYear, and dayOfWeek. weekOfYear follows the WEEK_OF_YEAR numbering. The dayOfWeek value must be one of the DAY_OF_WEEK values: SUNDAY to SATURDAY.

Note that the numeric day-of-week representation differs from the ISO 8601 standard, and that the weekOfYear numbering is compatible with the standard when getFirstDayOfWeek() is MONDAY and getMinimalDaysInFirstWeek() is 4.

Unlike the set method, all of the calendar fields and the instant of time value are calculated upon return.

If weekOfYear is out of the valid week-of-year range in weekYear, the weekYear and weekOfYear values are adjusted in lenient mode, or an IllegalArgumentException is thrown in non-lenient mode.

Parameters
weekYear	Int: the week year
weekOfYear	Int: the week number based on weekYear
dayOfWeek	Int: the day of week value: one of the constants for the DAY_OF_WEEK field: SUNDAY, ..., SATURDAY.

Exceptions
java.lang.IllegalArgumentException	if any of the given date specifiers is invalid, or if any of the calendar fields are inconsistent with the given date specifiers in non-lenient mode
java.lang.UnsupportedOperationException	if any week year numbering isn't supported in this Calendar.

See Also

• java.util.GregorianCalendar#isWeekDateSupported()
• java.util.Calendar#getFirstDayOfWeek()
• java.util.Calendar#getMinimalDaysInFirstWeek()

toZonedDateTime

Added in API level 26

open fun toZonedDateTime(): ZonedDateTime!

Converts this object to a ZonedDateTime that represents the same point on the time-line as this GregorianCalendar.

Since this object supports a Julian-Gregorian cutover date and ZonedDateTime does not, it is possible that the resulting year, month and day will have different values. The result will represent the correct date in the ISO calendar system, which will also be the same value for Modified Julian Days.

Return
ZonedDateTime!	a zoned date-time representing the same point on the time-line as this gregorian calendar

Protected methods

computeFields

Added in API level 1

protected open fun computeFields(): Unit

Converts the time value (millisecond offset from the Epoch) to calendar field values. The time is not recomputed first; to recompute the time, then the fields, call the complete method.

See Also

• java.util.Calendar#complete

computeTime

Added in API level 1

protected open fun computeTime(): Unit

Converts calendar field values to the time value (millisecond offset from the Epoch).

Exceptions
java.lang.IllegalArgumentException	if any calendar fields are invalid.