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Android Reference

Calendar


java.util

Class 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:

    1. 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.
    2. 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 and 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
      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
      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 and 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 specified TimeZone and Locale.
    • Method Summary

      Methods
      Modifier and Type Method and Description
      abstract void add(int field, int value)
      Adds the specified amount to a Calendar field.
      boolean after(Object calendar)
      Returns whether the Date specified by this Calendar instance is after the Date specified by the parameter.
      boolean before(Object calendar)
      Returns whether the Date specified by this Calendar instance is before the Date specified by the parameter.
      void clear()
      Clears all of the fields of this Calendar.
      void clear(int field)
      Clears the specified field to zero and sets the isSet flag to false.
      Object clone()
      Returns a new Calendar with the same properties.
      int compareTo(Calendar anotherCalendar)
      Compares the times of the two Calendar, which represent the milliseconds from the January 1, 1970 00:00:00.000 GMT (Gregorian).
      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 specified object to this Calendar and returns whether they are equal.
      int get(int field)
      Gets the value of the specified field after computing the field values by calling complete() first.
      int getActualMaximum(int field)
      Returns the maximum value of the specified field for the current date.
      int getActualMinimum(int field)
      Gets the minimum value of the specified 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()
      Gets the first day of the week for this Calendar.
      abstract int getGreatestMinimum(int field)
      Gets the greatest minimum value of the specified field.
      static Calendar getInstance()
      Constructs a new instance of the Calendar subclass appropriate for the default Locale.
      static Calendar getInstance(Locale locale)
      Constructs a new instance of the Calendar subclass appropriate for the specified Locale.
      static Calendar getInstance(TimeZone timezone)
      Constructs a new instance of the Calendar subclass appropriate for the default Locale, using the specified TimeZone.
      static Calendar getInstance(TimeZone timezone, Locale locale)
      Constructs a new instance of the Calendar subclass appropriate for the specified Locale.
      abstract int getLeastMaximum(int field)
      Gets the smallest maximum value of the specified field.
      abstract int getMaximum(int field)
      Gets the greatest maximum value of the specified field.
      int getMinimalDaysInFirstWeek()
      Gets the minimal days in the first week of the year.
      abstract int getMinimum(int field)
      Gets the smallest minimum value of the specified field.
      Date getTime()
      Gets the time of this Calendar as a Date object.
      long getTimeInMillis()
      Computes the time from the fields if required and returns the time.
      TimeZone getTimeZone()
      Gets the timezone of this Calendar.
      int hashCode()
      Returns an integer hash code for the receiver.
      protected int internalGet(int field)
      Gets the value of the specified field without recomputing.
      boolean isLenient()
      Returns if this Calendar accepts field values which are outside the valid range for the field.
      boolean isSet(int field)
      Returns whether the specified field is set.
      abstract void roll(int field, boolean increment)
      Increment or decrement the specified 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 specified amount to the specified 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 a field to the specified 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 this Calendar to accept 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.
      void setTimeZone(TimeZone timezone)
      Sets the TimeZone used by this Calendar.
      String toString()
      Returns the string representation of this Calendar.
    • Field Detail

      • 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
      • 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
      • 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_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
    • Constructor Detail

      • 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 specified TimeZone and Locale.
        Parameters:
        timezone - the timezone.
        locale - the locale.
    • Method Detail

      • add

        public abstract void add(int field,
               int value)
        Adds the specified 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 specified by this Calendar instance is after the Date specified 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 specified by this Calendar instance is before the Date specified 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 all of the fields of this Calendar. All fields are initialized to zero.
      • clear

        public final void clear(int field)
        Clears the specified field to zero and sets the isSet flag to false.
        Parameters:
        field - the field to clear.
      • clone

        public Object clone()
        Returns a new Calendar with the same properties.
        Overrides:
        clone in class Object
        Returns:
        a shallow copy of this Calendar.
        See Also:
        Cloneable
      • 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 specified 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 with this object.
        Returns:
        true if the specified object is equal to this Calendar, false otherwise.
        See Also:
        Object.hashCode()
      • get

        public int get(int field)
        Gets the value of the specified field after computing the field values by calling complete() first.
        Parameters:
        field - the field to get.
        Returns:
        the value of the specified field.
        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 specified field for the current date. For example, the maximum number of days in the current month.
      • getActualMinimum

        public int getActualMinimum(int field)
        Gets the minimum value of the specified field for the current date.
        Parameters:
        field - the field.
        Returns:
        the minimum value of the specified field.
      • 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()
        Gets the first day of the week for this Calendar.
        Returns:
        the first day of the week.
      • getGreatestMinimum

        public abstract int getGreatestMinimum(int field)
        Gets the greatest minimum value of the specified field. This is the biggest value that getActualMinimum can return for any possible time.
        Parameters:
        field - the field.
        Returns:
        the greatest minimum value of the specified field.
      • getInstance

        public static Calendar getInstance()
        Constructs a new instance of the Calendar subclass appropriate for the default Locale.
        Returns:
        a Calendar subclass instance set to the current date and time in the default Timezone.
      • getInstance

        public static Calendar getInstance(Locale locale)
        Constructs a new instance of the Calendar subclass appropriate for the specified Locale.
        Parameters:
        locale - the locale to use.
        Returns:
        a Calendar subclass instance 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, using the specified TimeZone.
        Parameters:
        timezone - the TimeZone to use.
        Returns:
        a Calendar subclass instance set to the current date and time in the specified timezone.
      • getInstance

        public static Calendar getInstance(TimeZone timezone,
                           Locale locale)
        Constructs a new instance of the Calendar subclass appropriate for the specified Locale.
        Parameters:
        timezone - the TimeZone to use.
        locale - the Locale to use.
        Returns:
        a Calendar subclass instance set to the current date and time in the specified timezone.
      • getLeastMaximum

        public abstract int getLeastMaximum(int field)
        Gets the smallest maximum value of the specified field. This is the smallest value that getActualMaximum() can return for any possible time.
        Parameters:
        field - the field number.
        Returns:
        the smallest maximum value of the specified field.
      • getMaximum

        public abstract int getMaximum(int field)
        Gets the greatest maximum value of the specified field. This returns the biggest value that get can return for the specified field.
        Parameters:
        field - the field.
        Returns:
        the greatest maximum value of the specified field.
      • getMinimalDaysInFirstWeek

        public int getMinimalDaysInFirstWeek()
        Gets the minimal days in the first week of the year.
        Returns:
        the minimal days in the first week of the year.
      • getMinimum

        public abstract int getMinimum(int field)
        Gets the smallest minimum value of the specified field. this returns the smallest value thet get can return for the specified field.
        Parameters:
        field - the field number.
        Returns:
        the smallest minimum value of the specified field.
      • getTime

        public final Date getTime()
        Gets the time of this Calendar as a Date object.
        Returns:
        a new Date initialized to the time of this Calendar.
        Throws:
        IllegalArgumentException - if the time is not set and the time cannot be computed from the current field values.
      • getTimeInMillis

        public long getTimeInMillis()
        Computes the time from the fields if required and returns the time.
        Returns:
        the time of this Calendar.
        Throws:
        IllegalArgumentException - if the time is not set and the time cannot be computed from the current field values.
      • getTimeZone

        public TimeZone getTimeZone()
        Gets the timezone of this Calendar.
        Returns:
        the TimeZone used by this Calendar.
      • hashCode

        public int hashCode()
        Returns an integer hash code for the receiver. Objects which are equal return the same value for this method.
        Overrides:
        hashCode in class Object
        Returns:
        the receiver's hash.
        See Also:
        equals(java.lang.Object)
      • internalGet

        protected final int internalGet(int field)
        Gets the value of the specified field without recomputing.
        Parameters:
        field - the field.
        Returns:
        the value of the specified field.
      • isLenient

        public boolean isLenient()
        Returns if this Calendar accepts field values which are outside the valid range for the field.
        Returns:
        true if this Calendar is lenient, false otherwise.
      • isSet

        public final boolean isSet(int field)
        Returns whether the specified 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.

        Parameters:
        field - a Calendar field number.
        Returns:
        true if the specified field is set, false otherwise.
      • roll

        public void roll(int field,
                int value)
        Adds the specified amount to the specified 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.
        Parameters:
        field - the field to roll.
        value - the amount to add.
      • roll

        public abstract void roll(int field,
                boolean increment)
        Increment or decrement the specified 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.
        Parameters:
        field - the number indicating the field to roll.
        increment - true to increment the field, false to decrement.
      • set

        public void set(int field,
               int value)
        Sets a field to the specified value.
        Parameters:
        field - the code indicating the Calendar field to modify.
        value - the 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.
        Parameters:
        year - the year.
        month - the month.
        day - the day of the month.
      • 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.
        Parameters:
        year - the year.
        month - the month.
        day - the day of the month.
        hourOfDay - the hour of day.
        minute - the minute.
      • 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.
        Parameters:
        year - the year.
        month - the month.
        day - the day of the month.
        hourOfDay - the hour of day.
        minute - the minute.
        second - the second.
      • setFirstDayOfWeek

        public void setFirstDayOfWeek(int value)
        Sets the first day of the week for this Calendar.
        Parameters:
        value - a Calendar day of the week.
      • setLenient

        public void setLenient(boolean value)
        Sets this Calendar to accept field values which are outside the valid range for the field.
        Parameters:
        value - a boolean value.
      • setMinimalDaysInFirstWeek

        public void setMinimalDaysInFirstWeek(int value)
        Sets the minimal days in the first week of the year.
        Parameters:
        value - the minimal days in the first week of the year.
      • setTime

        public final void setTime(Date date)
        Sets the time of this Calendar.
        Parameters:
        date - a Date object.
      • setTimeInMillis

        public void setTimeInMillis(long milliseconds)
        Sets the time of this Calendar.
        Parameters:
        milliseconds - the time as the number of milliseconds since Jan. 1, 1970.
      • setTimeZone

        public void setTimeZone(TimeZone timezone)
        Sets the TimeZone used by this Calendar.
        Parameters:
        timezone - a TimeZone.
      • toString

        public String toString()
        Returns the string representation of this Calendar.
        Overrides:
        toString in class Object
        Returns:
        a printable representation of this object.
      • compareTo

        public int compareTo(Calendar anotherCalendar)
        Compares the times of the two Calendar, which represent the milliseconds from the January 1, 1970 00:00:00.000 GMT (Gregorian).
        Specified by:
        compareTo in interface Comparable<Calendar>
        Parameters:
        anotherCalendar - another calendar that this one is compared with.
        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


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