java.util.Calendar

All Implemented Interfaces:: Serializable, Cloneable, Comparable<Calendar>

Direct Known Subclasses:: GregorianCalendar

public abstract class Calendar
extends Object
implements Serializable, Cloneable, Comparable<Calendar>

Calendar is an abstract base class for converting between a Date object and a set of integer fields such as YEAR, MONTH, DAY, HOUR, and so on. (A Date object represents a specific instant in time with millisecond precision. See Date for information about the Date class.)

Subclasses of Calendar interpret a Date according to the rules of a specific calendar system.

Like other locale-sensitive classes, Calendar provides a class method, getInstance, for getting a default instance of this class for general use. Calendar's getInstance method returns a calendar whose locale is based on system settings and whose time fields have been initialized with the current date and time:

Calendar rightNow = Calendar.getInstance()

A Calendar object can produce all the time field values needed to implement the date-time formatting for a particular language and calendar style (for example, Japanese-Gregorian, Japanese-Traditional). Calendar defines the range of values returned by certain fields, as well as their meaning. For example, the first month of the year has value MONTH == JANUARY for all calendars. Other values are defined by the concrete subclass, such as ERA and YEAR. See individual field documentation and subclass documentation for details.

When a Calendar is lenient, it accepts a wider range of field values than it produces. For example, a lenient GregorianCalendar interprets MONTH == JANUARY, DAY_OF_MONTH == 32 as February 1. A non-lenient GregorianCalendar throws an exception when given out-of-range field settings. When calendars recompute field values for return by get(), they normalize them. For example, a GregorianCalendar always produces DAY_OF_MONTH values between 1 and the length of the month.

Calendar defines a locale-specific seven day week using two parameters: the first day of the week and the minimal days in first week (from 1 to 7). These numbers are taken from the locale resource data when a Calendar is constructed. They may also be specified explicitly through the API.

When setting or getting the WEEK_OF_MONTH or WEEK_OF_YEAR fields, Calendar must determine the first week of the month or year as a reference point. The first week of a month or year is defined as the earliest seven day period beginning on getFirstDayOfWeek() and containing at least getMinimalDaysInFirstWeek() days of that month or year. Weeks numbered ..., -1, 0 precede the first week; weeks numbered 2, 3,... follow it. Note that the normalized numbering returned by get() may be different. For example, a specific Calendar subclass may designate the week before week 1 of a year as week n of the previous year.

When computing a Date from time fields, two special circumstances may arise: there may be insufficient information to compute the Date (such as only year and month but no day in the month), or there may be inconsistent information (such as "Tuesday, July 15, 1996" -- July 15, 1996 is actually a Monday).

Insufficient information. The calendar will use default information to specify the missing fields. This may vary by calendar; for the Gregorian calendar, the default for a field is the same as that of the start of the epoch: i.e., YEAR = 1970, MONTH = JANUARY, DATE = 1, etc.

Inconsistent information. If fields conflict, the calendar will give preference to fields set more recently. For example, when determining the day, the calendar will look for one of the following combinations of fields. The most recent combination, as determined by the most recently set single field, will be used.

 MONTH + DAY_OF_MONTH
 MONTH + WEEK_OF_MONTH + DAY_OF_WEEK
 MONTH + DAY_OF_WEEK_IN_MONTH + DAY_OF_WEEK
 DAY_OF_YEAR
 DAY_OF_WEEK + WEEK_OF_YEAR

For the time of day:

 HOUR_OF_DAY
 AM_PM + HOUR

Note: There are certain possible ambiguities in interpretation of certain singular times, which are resolved in the following ways:

24:00:00 "belongs" to the following day. That is, 23:59 on Dec 31, 1969 < 24:00 on Jan 1, 1970 < 24:01:00 on Jan 1, 1970 form a sequence of three consecutive minutes in time.
Although historically not precise, midnight also belongs to "am", and noon belongs to "pm", so on the same day, we have 12:00 am (midnight) < 12:01 am, and 12:00 pm (noon) < 12:01 pm

The date or time format strings are not part of the definition of a calendar, as those must be modifiable or overridable by the user at runtime. Use DateFormat to format dates.

Field manipulation methods

Calendar fields can be changed using three methods: set(), add(), and roll().

set(f, value) changes field f to value. In addition, it sets an internal member variable to indicate that field f has been changed. Although field f is changed immediately, the calendar's milliseconds is not recomputed until the next call to get(), getTime(), or getTimeInMillis() is made. Thus, multiple calls to set() do not trigger multiple, unnecessary computations. As a result of changing a field using set(), other fields may also change, depending on the field, the field value, and the calendar system. In addition, get(f) will not necessarily return value after the fields have been recomputed. The specifics are determined by the concrete calendar class.

Example: Consider a GregorianCalendar originally set to August 31, 1999. Calling set(Calendar.MONTH, Calendar.SEPTEMBER) sets the calendar to September 31, 1999. This is a temporary internal representation that resolves to October 1, 1999 if getTime()is then called. However, a call to set(Calendar.DAY_OF_MONTH, 30) before the call to getTime() sets the calendar to September 30, 1999, since no recomputation occurs after set() itself.

add(f, delta) adds delta to field f. This is equivalent to calling set(f, get(f) + delta) with two adjustments:

Add rule 1. The value of field f after the call minus the value of field f before the call is delta, modulo any overflow that has occurred in field f. 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 f 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.

In addition, unlike set(), add() forces an immediate recomputation of the calendar's milliseconds and all fields.

Example: Consider a GregorianCalendar originally set to August 31, 1999. Calling add(Calendar.MONTH, 13) sets the calendar to September 30, 2000. Add rule 1 sets the MONTH field to September, since adding 13 months to August gives September of the next year. Since DAY_OF_MONTH cannot be 31 in September in a GregorianCalendar, add rule 2 sets the DAY_OF_MONTH to 30, the closest possible value. Although it is a smaller field, DAY_OF_WEEK is not adjusted by rule 2, since it is expected to change when the month changes in a GregorianCalendar.

roll(f, delta) adds delta to field f without changing larger fields. This is equivalent to calling add(f, delta) with the following adjustment:

Roll rule. Larger fields are unchanged after the call. A larger field represents a larger unit of time. DAY_OF_MONTH is a larger field than HOUR.

Example: Consider a GregorianCalendar originally set to August 31, 1999. Calling roll(Calendar.MONTH, 8) sets the calendar to April 30, 1999. Add rule 1 sets the MONTH field to April. Using a GregorianCalendar, the DAY_OF_MONTH cannot be 31 in the month April. Add rule 2 sets it to the closest possible value, 30. Finally, the roll rule maintains the YEAR field value of 1999.

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).

Usage model. To motivate the behavior of add() and roll(), consider a user interface component with increment and decrement buttons for the month, day, and year, and an underlying GregorianCalendar. If the interface reads January 31, 1999 and the user presses the month increment button, what should it read? If the underlying implementation uses set(), it might read March 3, 1999. A better result would be February 28, 1999. Furthermore, if the user presses the month increment button again, it should read March 31, 1999, not March 28, 1999. By saving the original date and using either add() or roll(), depending on whether larger fields should be affected, the user interface can behave as most users will intuitively expect.

Note: You should always use roll and add rather than attempting to perform arithmetic operations directly on the fields of a Calendar. It is quite possible for Calendar subclasses to have fields with non-linear behavior, for example missing months or days during non-leap years. The subclasses' add and roll methods will take this into account, while simple arithmetic manipulations may give invalid results.

See Also:: Date, GregorianCalendar, TimeZone, Serialized Form

Field Summary

Fields
Modifier and Type	Field	Description
`static int`	`ALL_STYLES`	Requests both `SHORT` and `LONG` styles in the map returned by `getDisplayNames(int, int, java.util.Locale)`.
`static int`	`AM`	Value of the `AM_PM` field indicating the period of the day from midnight to just before noon.
`static int`	`AM_PM`	Field number for `get` and `set` indicating whether the `HOUR` is before or after noon.
`static int`	`APRIL`	Value of the `MONTH` field indicating the fourth month of the year.
`protected boolean`	`areFieldsSet`	True iff the values in `fields[]` correspond to `time`.
`static int`	`AUGUST`	Value of the `MONTH` field indicating the eighth month of the year.
`static int`	`DATE`	Field number for `get` and `set` indicating the day of the month.
`static int`	`DAY_OF_MONTH`	Field number for `get` and `set` indicating the day of the month.
`static int`	`DAY_OF_WEEK`	Field number for `get` and `set` indicating the day of the week.
`static 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.
`static int`	`DAY_OF_YEAR`	Field number for `get` and `set` indicating the day number within the current year.
`static int`	`DECEMBER`	Value of the `MONTH` field indicating the twelfth month of the year.
`static int`	`DST_OFFSET`	Field number for `get` and `set` indicating the daylight savings offset in milliseconds.
`static int`	`ERA`	Field number for `get` and `set` indicating the era, e.g., AD or BC in the Julian calendar.
`static int`	`FEBRUARY`	Value of the `MONTH` field indicating the second month of the year.
`static int`	`FIELD_COUNT`	This is the total number of fields in this calendar.
`protected int[]`	`fields`	Contains broken-down field values for the current value of `time` if `areFieldsSet` is true, or stale data corresponding to some previous value otherwise.
`static int`	`FRIDAY`	Value of the `DAY_OF_WEEK` field indicating Friday.
`static int`	`HOUR`	Field number for `get` and `set` indicating the hour of the morning or afternoon.
`static int`	`HOUR_OF_DAY`	Field number for `get` and `set` indicating the hour of the day.
`protected boolean[]`	`isSet`	Whether the corresponding element in `field[]` has been set.
`protected boolean`	`isTimeSet`	Whether `time` corresponds to the values in `fields[]`.
`static int`	`JANUARY`	Value of the `MONTH` field indicating the first month of the year.
`static int`	`JULY`	Value of the `MONTH` field indicating the seventh month of the year.
`static int`	`JUNE`	Value of the `MONTH` field indicating the sixth month of the year.
`static int`	`LONG`	Requests long names (such as "January") from `getDisplayName(int, int, java.util.Locale)` or `getDisplayNames(int, int, java.util.Locale)`.
`static int`	`MARCH`	Value of the `MONTH` field indicating the third month of the year.
`static int`	`MAY`	Value of the `MONTH` field indicating the fifth month of the year.
`static int`	`MILLISECOND`	Field number for `get` and `set` indicating the millisecond within the second.
`static int`	`MINUTE`	Field number for `get` and `set` indicating the minute within the hour.
`static int`	`MONDAY`	Value of the `DAY_OF_WEEK` field indicating Monday.
`static int`	`MONTH`	Field number for `get` and `set` indicating the month.
`static int`	`NOVEMBER`	Value of the `MONTH` field indicating the eleventh month of the year.
`static int`	`OCTOBER`	Value of the `MONTH` field indicating the tenth month of the year.
`static int`	`PM`	Value of the `AM_PM` field indicating the period of the day from noon to just before midnight.
`static int`	`SATURDAY`	Value of the `DAY_OF_WEEK` field indicating Saturday.
`static int`	`SECOND`	Field number for `get` and `set` indicating the second within the minute.
`static int`	`SEPTEMBER`	Value of the `MONTH` field indicating the ninth month of the year.
`static int`	`SHORT`	Requests short names (such as "Jan") from `getDisplayName(int, int, java.util.Locale)` or `getDisplayNames(int, int, java.util.Locale)`.
`static int`	`SUNDAY`	Value of the `DAY_OF_WEEK` field indicating Sunday.
`static int`	`THURSDAY`	Value of the `DAY_OF_WEEK` field indicating Thursday.
`protected long`	`time`	A time in milliseconds since January 1, 1970.
`static int`	`TUESDAY`	Value of the `DAY_OF_WEEK` field indicating Tuesday.
`static int`	`UNDECIMBER`	Value of the `MONTH` field indicating the thirteenth month of the year.
`static int`	`WEDNESDAY`	Value of the `DAY_OF_WEEK` field indicating Wednesday.
`static int`	`WEEK_OF_MONTH`	Field number for `get` and `set` indicating the week number within the current month.
`static int`	`WEEK_OF_YEAR`	Field number for `get` and `set` indicating the week number within the current year.
`static int`	`YEAR`	Field number for `get` and `set` indicating the year.
`static int`	`ZONE_OFFSET`	Field number for `get` and `set` indicating the raw offset from GMT in milliseconds.

Constructor Summary

Constructors
Modifier	Constructor	Description
`protected`	`Calendar()`	Constructs a `Calendar` instance using the default `TimeZone` and `Locale`.
`protected`	`Calendar(TimeZone timezone, Locale locale)`	Constructs a `Calendar` instance using the given `TimeZone` and `Locale`.

Method Summary

Modifier and Type	Method	Description
`abstract void`	`add(int field, int value)`	Adds the given amount to a `Calendar` field.
`boolean`	`after(Object calendar)`	Returns whether the `Date` represented by this `Calendar` instance is after the `Date` represented by the parameter.
`boolean`	`before(Object calendar)`	Returns whether the `Date` represented by this `Calendar` instance is before the `Date` represented by the parameter.
`void`	`clear()`	Clears the values of all the time fields, marking them all unset and assigning them all a value of zero.
`void`	`clear(int field)`	Clears the value in the given time field, marking it unset and assigning it a value of zero.
`Object`	`clone()`	Returns a shallow copy of this `Calendar` with the same properties.
`int`	`compareTo(Calendar anotherCalendar)`	Compares the time represented by this `Calendar` to that represented by the given `Calendar`.
`protected void`	`complete()`	Computes the time from the fields if the time has not already been set.
`protected abstract void`	`computeFields()`	Computes the `Calendar` fields from `time`.
`protected abstract void`	`computeTime()`	Computes `time` from the Calendar fields.
`boolean`	`equals(Object object)`	Compares the given object to this `Calendar` and returns whether they are equal.
`int`	`get(int field)`	Returns the value of the given field after computing the field values by calling `complete()` first.
`int`	`getActualMaximum(int field)`	Returns the maximum value of the given field for the current date.
`int`	`getActualMinimum(int field)`	Returns the minimum value of the given field for the current date.
`static Locale[]`	`getAvailableLocales()`	Returns an array of locales for which custom `Calendar` instances are available.
`String`	`getDisplayName(int field, int style, Locale locale)`	Returns a human-readable string for the value of `field` using the given style and locale.
`Map<String,Integer>`	`getDisplayNames(int field, int style, Locale locale)`	Returns a map of human-readable strings to corresponding values, for the given field, style, and locale.
`int`	`getFirstDayOfWeek()`	Returns the first day of the week for this `Calendar`.
`abstract int`	`getGreatestMinimum(int field)`	Returns the greatest minimum value of the given field.
`static Calendar`	`getInstance()`	Constructs a new instance of the `Calendar` subclass appropriate for the default `Locale` and default `TimeZone`, set to the current date and time.
`static Calendar`	`getInstance(Locale locale)`	Constructs a new instance of the `Calendar` subclass appropriate for the given `Locale` and default `TimeZone`, set to the current date and time.
`static Calendar`	`getInstance(TimeZone timezone)`	Constructs a new instance of the `Calendar` subclass appropriate for the default `Locale` and given `TimeZone`, set to the current date and time.
`static Calendar`	`getInstance(TimeZone timezone, Locale locale)`	Constructs a new instance of the `Calendar` subclass appropriate for the given `Locale` and given `TimeZone`, set to the current date and time.
`abstract int`	`getLeastMaximum(int field)`	Returns the smallest maximum value of the given field.
`abstract int`	`getMaximum(int field)`	Returns the greatest maximum value of the given field.
`int`	`getMinimalDaysInFirstWeek()`	Returns the minimal days in the first week of the year.
`abstract int`	`getMinimum(int field)`	Returns the smallest minimum value of the given field.
`Date`	`getTime()`	Returns the time of this `Calendar` as a `Date` object.
`long`	`getTimeInMillis()`	Returns the time represented by this `Calendar`, recomputing the time from its fields if necessary.
`TimeZone`	`getTimeZone()`	Returns the time zone used by this `Calendar`.
`int`	`hashCode()`	Returns an integer hash code for this object.
`protected int`	`internalGet(int field)`	Returns the value of the given field without recomputing.
`boolean`	`isLenient()`	Tests whether this `Calendar` accepts field values which are outside the valid range for the field.
`boolean`	`isSet(int field)`	Tests whether the given field is set.
`abstract void`	`roll(int field, boolean increment)`	Increment or decrement the given field and wrap the value of the field when it goes beyond the maximum or minimum value for the current date.
`void`	`roll(int field, int value)`	Adds the given amount to the given field and wraps the value of the field when it goes beyond the maximum or minimum value for the current date.
`void`	`set(int field, int value)`	Sets the given field to the given value.
`void`	`set(int year, int month, int day)`	Sets the year, month, and day of the month fields.
`void`	`set(int year, int month, int day, int hourOfDay, int minute)`	Sets the year, month, day of the month, hour of day, and minute fields.
`void`	`set(int year, int month, int day, int hourOfDay, int minute, int second)`	Sets the year, month, day of the month, hour of day, minute, and second fields.
`void`	`setFirstDayOfWeek(int value)`	Sets the first day of the week for this `Calendar`.
`void`	`setLenient(boolean value)`	Sets whether this `Calendar` accepts field values which are outside the valid range for the field.
`void`	`setMinimalDaysInFirstWeek(int value)`	Sets the minimal days in the first week of the year.
`void`	`setTime(Date date)`	Sets the time of this `Calendar`.
`void`	`setTimeInMillis(long milliseconds)`	Sets the time of this `Calendar` to the given Unix time.
`void`	`setTimeZone(TimeZone timezone)`	Sets the `TimeZone` used by this Calendar.
`String`	`toString()`	Returns a string representation of this `Calendar`, showing which fields are set.

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details
- areFieldsSet
  
  protected boolean areFieldsSet
  
  True iff the values in fields[] correspond to time. Despite the name, this is effectively "are the values in fields[] up-to-date?" --- fields[] may contain non-zero values and isSet[] may contain true values even when areFieldsSet is false. Accessing the fields via get will ensure the fields are up-to-date.
- fields
  
  protected int[] fields
  
  Contains broken-down field values for the current value of time if areFieldsSet is true, or stale data corresponding to some previous value otherwise. Accessing the fields via get will ensure the fields are up-to-date. The array length is always FIELD_COUNT.
- isSet
  
  protected boolean[] isSet
  
  Whether the corresponding element in field[] has been set. Initially, these are all false. The first time the fields are computed, these are set to true and remain set even if the data becomes stale: you must check areFieldsSet if you want to know whether the value is up-to-date. Note that isSet is not a safe alternative to accessing this array directly, and will likewise return stale data! The array length is always FIELD_COUNT.
- isTimeSet
  
  protected boolean isTimeSet
  
  Whether time corresponds to the values in fields[]. If false, time is out-of-date with respect to changes fields[]. Accessing the time via getTimeInMillis will always return the correct value.
- time
  
  protected long time
  
  A time in milliseconds since January 1, 1970. See isTimeSet. Accessing the time via getTimeInMillis will always return the correct value.
- JANUARY
  
  public static final int JANUARY
  
  Value of the MONTH field indicating the first month of the year.
  
  See Also:
  
  Constant Field Values
- FEBRUARY
  
  public static final int FEBRUARY
  
  Value of the MONTH field indicating the second month of the year.
  
  See Also:
  
  Constant Field Values
- MARCH
  
  public static final int MARCH
  
  Value of the MONTH field indicating the third month of the year.
  
  See Also:
  
  Constant Field Values
- APRIL
  
  public static final int APRIL
  
  Value of the MONTH field indicating the fourth month of the year.
  
  See Also:
  
  Constant Field Values
- MAY
  
  public static final int MAY
  
  Value of the MONTH field indicating the fifth month of the year.
  
  See Also:
  
  Constant Field Values
- JUNE
  
  public static final int JUNE
  
  Value of the MONTH field indicating the sixth month of the year.
  
  See Also:
  
  Constant Field Values
- JULY
  
  public static final int JULY
  
  Value of the MONTH field indicating the seventh month of the year.
  
  See Also:
  
  Constant Field Values
- AUGUST
  
  public static final int AUGUST
  
  Value of the MONTH field indicating the eighth month of the year.
  
  See Also:
  
  Constant Field Values
- SEPTEMBER
  
  public static final int SEPTEMBER
  
  Value of the MONTH field indicating the ninth month of the year.
  
  See Also:
  
  Constant Field Values
- OCTOBER
  
  public static final int OCTOBER
  
  Value of the MONTH field indicating the tenth month of the year.
  
  See Also:
  
  Constant Field Values
- NOVEMBER
  
  public static final int NOVEMBER
  
  Value of the MONTH field indicating the eleventh month of the year.
  
  See Also:
  
  Constant Field Values
- DECEMBER
  
  public static final int DECEMBER
  
  Value of the MONTH field indicating the twelfth month of the year.
  
  See Also:
  
  Constant Field Values
- UNDECIMBER
  
  public static final int UNDECIMBER
  
  Value of the MONTH field indicating the thirteenth month of the year. Although GregorianCalendar does not use this value, lunar calendars do.
  
  See Also:
  
  Constant Field Values
- SUNDAY
  
  public static final int SUNDAY
  
  Value of the DAY_OF_WEEK field indicating Sunday.
  
  See Also:
  
  Constant Field Values
- MONDAY
  
  public static final int MONDAY
  
  Value of the DAY_OF_WEEK field indicating Monday.
  
  See Also:
  
  Constant Field Values
- TUESDAY
  
  public static final int TUESDAY
  
  Value of the DAY_OF_WEEK field indicating Tuesday.
  
  See Also:
  
  Constant Field Values
- WEDNESDAY
  
  public static final int WEDNESDAY
  
  Value of the DAY_OF_WEEK field indicating Wednesday.
  
  See Also:
  
  Constant Field Values
- THURSDAY
  
  public static final int THURSDAY
  
  Value of the DAY_OF_WEEK field indicating Thursday.
  
  See Also:
  
  Constant Field Values
- FRIDAY
  
  public static final int FRIDAY
  
  Value of the DAY_OF_WEEK field indicating Friday.
  
  See Also:
  
  Constant Field Values
- SATURDAY
  
  public static final int SATURDAY
  
  Value of the DAY_OF_WEEK field indicating Saturday.
  
  See Also:
  
  Constant Field Values
- ERA
  
  public static final 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.
  
  See Also:
  
  GregorianCalendar.AD, GregorianCalendar.BC, Constant Field Values
- YEAR
  
  public static final int YEAR
  
  Field number for get and set indicating the year. This is a calendar-specific value; see subclass documentation.
  
  See Also:
  
  Constant Field Values
- MONTH
  
  public static final int MONTH
  
  Field number for get and set indicating the month. This is a calendar-specific value. The first month of the year is JANUARY; the last depends on the number of months in a year.
  
  See Also:
  
  JANUARY, FEBRUARY, MARCH, APRIL, MAY, JUNE, JULY, AUGUST, SEPTEMBER, OCTOBER, NOVEMBER, DECEMBER, UNDECIMBER, Constant Field Values
- WEEK_OF_YEAR
  
  public static final 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.
  
  See Also:
  
  getFirstDayOfWeek(), getMinimalDaysInFirstWeek(), Constant Field Values
- WEEK_OF_MONTH
  
  public static final 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.
  
  See Also:
  
  getFirstDayOfWeek(), getMinimalDaysInFirstWeek(), Constant Field Values
- DATE
  
  public static final 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.
  
  See Also:
  
  DAY_OF_MONTH, Constant Field Values
- DAY_OF_MONTH
  
  public static final 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.
  
  See Also:
  
  DATE, Constant Field Values
- DAY_OF_YEAR
  
  public static final 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.
  
  See Also:
  
  Constant Field Values
- DAY_OF_WEEK
  
  public static final 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.
  
  See Also:
  
  SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, Constant Field Values
- DAY_OF_WEEK_IN_MONTH
  
  public static final 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 15 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.
  
  See Also:
  
  DAY_OF_WEEK, WEEK_OF_MONTH, Constant Field Values
- AM_PM
  
  public static final 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.
  
  See Also:
  
  AM, PM, HOUR, Constant Field Values
- HOUR
  
  public static final int HOUR
  
  Field number for get and set indicating the hour of the morning or afternoon. HOUR is used for the 12-hour clock. E.g., at 10:04:15.250 PM the HOUR is 10.
  
  See Also:
  
  AM_PM, HOUR_OF_DAY, Constant Field Values
- HOUR_OF_DAY
  
  public static final 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.
  
  See Also:
  
  HOUR, Constant Field Values
- MINUTE
  
  public static final 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.
  
  See Also:
  
  Constant Field Values
- SECOND
  
  public static final 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.
  
  See Also:
  
  Constant Field Values
- MILLISECOND
  
  public static final 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.
  
  See Also:
  
  Constant Field Values
- ZONE_OFFSET
  
  public static final int ZONE_OFFSET
  
  Field number for get and set indicating the raw offset from GMT in milliseconds.
  
  See Also:
  
  Constant Field Values
- DST_OFFSET
  
  public static final int DST_OFFSET
  
  Field number for get and set indicating the daylight savings offset in milliseconds.
  
  See Also:
  
  Constant Field Values
- FIELD_COUNT
  
  public static final int FIELD_COUNT
  
  This is the total number of fields in this calendar.
  
  See Also:
  
  Constant Field Values
- AM
  
  public static final int AM
  
  Value of the AM_PM field indicating the period of the day from midnight to just before noon.
  
  See Also:
  
  Constant Field Values
- PM
  
  public static final int PM
  
  Value of the AM_PM field indicating the period of the day from noon to just before midnight.
  
  See Also:
  
  Constant Field Values
- ALL_STYLES
  
  public static final int ALL_STYLES
  
  Requests both SHORT and LONG styles in the map returned by getDisplayNames(int, int, java.util.Locale).
  
  Since:
  
  1.6
  
  See Also:
  
  Constant Field Values
- SHORT
  
  public static final int SHORT
  
  Requests short names (such as "Jan") from getDisplayName(int, int, java.util.Locale) or getDisplayNames(int, int, java.util.Locale).
  
  Since:
  
  1.6
  
  See Also:
  
  Constant Field Values
- LONG
  
  public static final int LONG
  
  Requests long names (such as "January") from getDisplayName(int, int, java.util.Locale) or getDisplayNames(int, int, java.util.Locale).
  
  Since:
  
  1.6
  
  See Also:
  
  Constant Field Values
Constructor Details
- Calendar
  
  protected Calendar()
  
  Constructs a Calendar instance using the default TimeZone and Locale.
- Calendar
  
  protected Calendar(TimeZone timezone, Locale locale)
  
  Constructs a Calendar instance using the given TimeZone and Locale.
Method Details
- add
  
  public abstract void add(int field, int value)
  
  Adds the given amount to a Calendar field.
  
  Parameters:
  
  field - the Calendar field to modify.
  
  value - the amount to add to the field.
  
  Throws:
  
  IllegalArgumentException - if field is DST_OFFSET or ZONE_OFFSET.
- after
  
  public boolean after(Object calendar)
  
  Returns whether the Date represented by this Calendar instance is after the Date represented by the parameter. The comparison is not dependent on the time zones of the Calendar.
  
  Parameters:
  
  calendar - the Calendar instance to compare.
  
  Returns:
  
  true when this Calendar is after calendar, false otherwise.
  
  Throws:
  
  IllegalArgumentException - if the time is not set and the time cannot be computed from the current field values.
- before
  
  public boolean before(Object calendar)
  
  Returns whether the Date represented by this Calendar instance is before the Date represented by the parameter. The comparison is not dependent on the time zones of the Calendar.
  
  Parameters:
  
  calendar - the Calendar instance to compare.
  
  Returns:
  
  true when this Calendar is before calendar, false otherwise.
  
  Throws:
  
  IllegalArgumentException - if the time is not set and the time cannot be computed from the current field values.
- clear
  
  public final void clear()
  
  Clears the values of all the time fields, marking them all unset and assigning them all a value of zero. The actual field values will be determined the next time the fields are accessed.
- clear
  
  public final void clear(int field)
  
  Clears the value in the given time field, marking it unset and assigning it a value of zero. The actual field value will be determined the next time the field is accessed.
- clone
  
  public Object clone()
  
  Returns a shallow copy of this Calendar with the same properties.
  
  Overrides:
  
  clone in class Object
  
  Returns:
  
  a copy of this object.
- complete
  
  protected void complete()
  
  Computes the time from the fields if the time has not already been set. Computes the fields from the time if the fields are not already set.
  
  Throws:
  
  IllegalArgumentException - if the time is not set and the time cannot be computed from the current field values.
- computeFields
  
  protected abstract void computeFields()
  
  Computes the Calendar fields from time.
- computeTime
  
  protected abstract void computeTime()
  
  Computes time from the Calendar fields.
  
  Throws:
  
  IllegalArgumentException - if the time cannot be computed from the current field values.
- equals
  
  public boolean equals(Object object)
  
  Compares the given object to this Calendar and returns whether they are equal. The object must be an instance of Calendar and have the same properties.
  
  Overrides:
  
  equals in class Object
  
  Parameters:
  
  object - the object to compare this instance with.
  
  Returns:
  
  true if the given object is equal to this Calendar, false otherwise.
  
  See Also:
  
  Object.hashCode()
- get
  
  public int get(int field)
  
  Returns the value of the given field after computing the field values by calling complete() first.
  
  Throws:
  
  IllegalArgumentException - if the fields are not set, the time is not set, and the time cannot be computed from the current field values.
  
  ArrayIndexOutOfBoundsException - if the field is not inside the range of possible fields. The range is starting at 0 up to FIELD_COUNT.
- getActualMaximum
  
  public int getActualMaximum(int field)
  
  Returns the maximum value of the given field for the current date. For example, the maximum number of days in the current month.
- getActualMinimum
  
  public int getActualMinimum(int field)
  
  Returns the minimum value of the given field for the current date.
- getAvailableLocales
  
  public static Locale[] getAvailableLocales()
  
  Returns an array of locales for which custom Calendar instances are available.
  Note that Android does not support user-supplied locale service providers.
- getFirstDayOfWeek
  
  public int getFirstDayOfWeek()
  
  Returns the first day of the week for this Calendar.
- getGreatestMinimum
  
  public abstract int getGreatestMinimum(int field)
  
  Returns the greatest minimum value of the given field. This is the biggest value that getActualMinimum can return for any possible time.
- getInstance
  
  public static Calendar getInstance()
  
  Constructs a new instance of the Calendar subclass appropriate for the default Locale and default TimeZone, set to the current date and time.
- getInstance
  
  public static Calendar getInstance(Locale locale)
  
  Constructs a new instance of the Calendar subclass appropriate for the given Locale and default TimeZone, set to the current date and time.
- getInstance
  
  public static Calendar getInstance(TimeZone timezone)
  
  Constructs a new instance of the Calendar subclass appropriate for the default Locale and given TimeZone, set to the current date and time.
- getInstance
  
  public static Calendar getInstance(TimeZone timezone, Locale locale)
  
  Constructs a new instance of the Calendar subclass appropriate for the given Locale and given TimeZone, set to the current date and time.
- getLeastMaximum
  
  public abstract int getLeastMaximum(int field)
  
  Returns the smallest maximum value of the given field. This is the smallest value that getActualMaximum() can return for any possible time.
- getMaximum
  
  public abstract int getMaximum(int field)
  
  Returns the greatest maximum value of the given field. This returns the biggest value that get can return for the given field.
- getMinimalDaysInFirstWeek
  
  public int getMinimalDaysInFirstWeek()
  
  Returns the minimal days in the first week of the year.
- getMinimum
  
  public abstract int getMinimum(int field)
  
  Returns the smallest minimum value of the given field. this returns the smallest value that get can return for the given field.
- getTime
  
  public final Date getTime()
  
  Returns the time of this Calendar as a Date object.
  
  Throws:
  
  IllegalArgumentException - if the time is not set and the time cannot be computed from the current field values.
- getTimeInMillis
  
  public long getTimeInMillis()
  
  Returns the time represented by this Calendar, recomputing the time from its fields if necessary.
  
  Throws:
  
  IllegalArgumentException - if the time is not set and the time cannot be computed from the current field values.
- getTimeZone
  
  public TimeZone getTimeZone()
  
  Returns the time zone used by this Calendar.
- hashCode
  
  public int hashCode()
  
  Description copied from class: Object
  
  Returns an integer hash code for this object. By contract, any two objects for which Object.equals(java.lang.Object) returns true must return the same hash code value. This means that subclasses of Object usually override both methods or neither method.
  Note that hash values must not change over time unless information used in equals comparisons also changes.
  See Writing a correct hashCode method if you intend implementing your own hashCode method.
  
  Overrides:
  
  hashCode in class Object
  
  Returns:
  
  this object's hash code.
  
  See Also:
  
  Object.equals(java.lang.Object)
- internalGet
  
  protected final int internalGet(int field)
  
  Returns the value of the given field without recomputing.
- isLenient
  
  public boolean isLenient()
  
  Tests whether this Calendar accepts field values which are outside the valid range for the field.
- isSet
  
  public final boolean isSet(int field)
  
  Tests whether the given field is set. Note that the interpretation of "is set" is somewhat technical. In particular, it does not mean that the field's value is up to date. If you want to know whether a field contains an up-to-date value, you must also check areFieldsSet, making this method somewhat useless unless you're a subclass, in which case you can access the isSet array directly.
  A field remains "set" from the first time its value is computed until it's cleared by one of the clear methods. Thus "set" does not mean "valid". You probably want to call get -- which will update fields as necessary -- rather than try to make use of this method.
- roll
  
  public void roll(int field, int value)
  
  Adds the given amount to the given field and wraps the value of the field when it goes beyond the maximum or minimum value for the current date. Other fields will be adjusted as required to maintain a consistent date.
- roll
  
  public abstract void roll(int field, boolean increment)
  
  Increment or decrement the given field and wrap the value of the field when it goes beyond the maximum or minimum value for the current date. Other fields will be adjusted as required to maintain a consistent date.
- set
  
  public void set(int field, int value)
  
  Sets the given field to the given value.
- set
  
  public final void set(int year, int month, int day)
  
  Sets the year, month, and day of the month fields. Other fields are not changed; call clear() first if this is not desired. The month value is 0-based, so it may be clearer to use a constant like JANUARY.
- set
  
  public final void set(int year, int month, int day, int hourOfDay, int minute)
  
  Sets the year, month, day of the month, hour of day, and minute fields. Other fields are not changed; call clear() first if this is not desired. The month value is 0-based, so it may be clearer to use a constant like JANUARY.
- set
  
  public final void set(int year, int month, int day, int hourOfDay, int minute, int second)
  
  Sets the year, month, day of the month, hour of day, minute, and second fields. Other fields are not changed; call clear() first if this is not desired. The month value is 0-based, so it may be clearer to use a constant like JANUARY.
- setFirstDayOfWeek
  
  public void setFirstDayOfWeek(int value)
  
  Sets the first day of the week for this Calendar. The value should be a day of the week such as MONDAY.
- setLenient
  
  public void setLenient(boolean value)
  
  Sets whether this Calendar accepts field values which are outside the valid range for the field.
- setMinimalDaysInFirstWeek
  
  public void setMinimalDaysInFirstWeek(int value)
  
  Sets the minimal days in the first week of the year.
- setTime
  
  public final void setTime(Date date)
  
  Sets the time of this Calendar.
- setTimeInMillis
  
  public void setTimeInMillis(long milliseconds)
  
  Sets the time of this Calendar to the given Unix time. See Date for more about what this means.
- setTimeZone
  
  public void setTimeZone(TimeZone timezone)
  
  Sets the TimeZone used by this Calendar.
- toString
  
  public String toString()
  
  Returns a string representation of this Calendar, showing which fields are set.
  
  Overrides:
  
  toString in class Object
  
  Returns:
  
  a printable representation of this object.
- compareTo
  
  public int compareTo(Calendar anotherCalendar)
  
  Compares the time represented by this Calendar to that represented by the given Calendar.
  
  Specified by:
  
  compareTo in interface Comparable<Calendar>
  
  Parameters:
  
  anotherCalendar - the object to compare to this instance.
  
  Returns:
  
  0 if the times of the two Calendars are equal, -1 if the time of this Calendar is before the other one, 1 if the time of this Calendar is after the other one.
  
  Throws:
  
  NullPointerException - if the argument is null.
  
  IllegalArgumentException - if the argument does not include a valid time value.
- getDisplayName
  
  public String getDisplayName(int field, int style, Locale locale)
  
  Returns a human-readable string for the value of field using the given style and locale. If no string is available, returns null. The value is retrieved by invoking get(field).
  For example, getDisplayName(MONTH, SHORT, Locale.US) will return "Jan" while getDisplayName(MONTH, LONG, Locale.US) will return "January".
  
  Parameters:
  
  field - the field
  
  style - SHORT or LONG
  
  locale - the locale
  
  Returns:
  
  the display name, or null
  
  Throws:
  
  NullPointerException - if locale == null
  
  IllegalArgumentException - if field or style is invalid
  
  Since:
  
  1.6
- getDisplayNames
  
  public Map<String,Integer> getDisplayNames(int field, int style, Locale locale)
  
  Returns a map of human-readable strings to corresponding values, for the given field, style, and locale. Returns null if no strings are available.
  For example, getDisplayNames(MONTH, ALL_STYLES, Locale.US) would contain mappings from "Jan" and "January" to JANUARY, and so on.
  
  Parameters:
  
  field - the field
  
  style - SHORT, LONG, or ALL_STYLES
  
  locale - the locale
  
  Returns:
  
  the display name, or null
  
  Throws:
  
  NullPointerException - if locale == null
  
  IllegalArgumentException - if field or style is invalid
  
  Since:
  
  1.6

Class Calendar

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Details

areFieldsSet

fields

isSet

isTimeSet

time

JANUARY

FEBRUARY

MARCH

APRIL

MAY

JUNE

JULY

AUGUST

SEPTEMBER

OCTOBER

NOVEMBER

DECEMBER

UNDECIMBER

SUNDAY

MONDAY

TUESDAY

WEDNESDAY

THURSDAY

FRIDAY

SATURDAY

ERA

YEAR

MONTH

WEEK_OF_YEAR

WEEK_OF_MONTH

DATE

DAY_OF_MONTH

DAY_OF_YEAR

DAY_OF_WEEK

DAY_OF_WEEK_IN_MONTH

AM_PM

HOUR

HOUR_OF_DAY

MINUTE

SECOND

MILLISECOND

ZONE_OFFSET

DST_OFFSET

FIELD_COUNT

AM

PM

ALL_STYLES

SHORT

LONG

Constructor Details

Calendar

Calendar

Method Details

add

after

before

clear

clear

clone

complete

computeFields

computeTime

equals

get

getActualMaximum

getActualMinimum

getAvailableLocales

getFirstDayOfWeek

getGreatestMinimum

getInstance

getInstance

getInstance

getInstance

getLeastMaximum