- All Implemented Interfaces:
Serializable
,Cloneable
,Comparable<Calendar>
- Direct Known Subclasses:
GregorianCalendar
Calendar
class is an abstract class that provides methods
for converting between a specific instant in time and a set of calendar fields
such as YEAR
, MONTH
,
DAY_OF_MONTH
, HOUR
, and so on, and for
manipulating the calendar fields, such as getting the date of the next
week. An instant in time can be represented by a millisecond value that is
an offset from the Epoch, January 1, 1970
00:00:00.000 GMT (Gregorian).
The class also provides additional fields and methods for
implementing a concrete calendar system outside the package. Those
fields and methods are defined as protected
.
Like other locale-sensitive classes, Calendar
provides a
class method, getInstance
, for getting a generally useful
object of this type. Calendar
's getInstance
method
returns a Calendar
object whose
calendar fields have been initialized with the current date and time:
Calendar rightNow = Calendar.getInstance();
A Calendar
object can produce all the calendar 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 calendar fields, as well as their meaning. For example,
the first month of the calendar system has value MONTH ==
JANUARY
for all calendars. Other values are defined by the
concrete subclass, such as ERA
. See individual field
documentation and subclass documentation for details.
Getting and Setting Calendar Field Values
The calendar field values can be set by calling the set
methods. Any field values set in a Calendar
will not be
interpreted until it needs to calculate its time value (milliseconds from
the Epoch) or values of the calendar fields. Calling the
get
, getTimeInMillis
, getTime
,
add
and roll
involves such calculation.
Unless otherwise specified, any Calendar
method containing the
parameter int field
will throw an ArrayIndexOutOfBoundsException
if the specified field is out of range (field
< 0 ||
field
>= FIELD_COUNT
).
Leniency
Calendar
has two modes for interpreting the calendar
fields, lenient and non-lenient. When a
Calendar
is in lenient mode, it accepts a wider range of
calendar field values than it produces. When a Calendar
recomputes calendar field values for return by get()
, all of
the calendar fields are normalized. For example, a lenient
GregorianCalendar
interprets MONTH == JANUARY
,
DAY_OF_MONTH == 32
as February 1.
When a Calendar
is in non-lenient mode, it throws an
exception if there is any inconsistency in its calendar fields. For
example, a GregorianCalendar
always produces
DAY_OF_MONTH
values between 1 and the length of the month. A
non-lenient GregorianCalendar
throws an exception upon
calculating its time or calendar field values if any out-of-range field
value has been set.
First Week
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 or the
locale itself when a Calendar
is constructed. If the designated
locale contains "fw" and/or "rg"
Unicode extensions, the first day of the week will be obtained according to
those extensions. If both "fw" and "rg" are specified, the value from the "fw"
extension supersedes the implicit one from the "rg" extension.
They may also be specified explicitly through the methods for setting their
values.
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.
Calendar Fields Resolution
When computing a date and time from the calendar fields, there may be insufficient information for the computation (such as only year and month with no day of month), or there may be inconsistent information (such as Tuesday, July 15, 1996 (Gregorian) -- July 15, 1996 is actually a Monday).Calendar
will resolve
calendar field values to determine the date and time in the
following way.
If there is any conflict in calendar field values,
Calendar
gives priorities to calendar fields that have been set
more recently. The following are the default combinations of the
calendar fields. The most recent combination, as determined by the
most recently set single field, will be used.
For the time of day fields:YEAR + MONTH + DAY_OF_MONTH YEAR + MONTH + WEEK_OF_MONTH + DAY_OF_WEEK YEAR + MONTH + DAY_OF_WEEK_IN_MONTH + DAY_OF_WEEK YEAR + DAY_OF_YEAR YEAR + DAY_OF_WEEK + WEEK_OF_YEAR
HOUR_OF_DAY AM_PM + HOUR
If there are any calendar fields whose values haven't been set in the selected
field combination, Calendar
uses their default values. The default
value of each field may vary by concrete calendar systems. For example, in
GregorianCalendar
, the default of a field is the same as that
of the start of the Epoch: i.e., YEAR = 1970
, MONTH =
JANUARY
, DAY_OF_MONTH = 1
, etc.
Note: There are certain possible ambiguities in interpretation of certain singular times, which are resolved in the following ways:
- 23:59 is the last minute of the day and 00:00 is the first minute of the next day. Thus, 23:59 on Dec 31, 1999 < 00:00 on Jan 1, 2000 < 00:01 on Jan 1, 2000.
- Although historically not precise, midnight also belongs to "am", and noon belongs to "pm", so on the same day, 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
The calendar fields can be changed using three methods:set()
, add()
, and roll()
.
set(f, value)
changes calendar field
f
to value
. In addition, it sets an
internal member variable to indicate that calendar field f
has
been changed. Although calendar field f
is changed immediately,
the calendar's time value in milliseconds is not recomputed until the next call to
get()
, getTime()
, getTimeInMillis()
,
add()
, or roll()
is made. Thus, multiple calls to
set()
do not trigger multiple, unnecessary
computations. As a result of changing a calendar field using
set()
, other calendar fields may also change, depending on the
calendar field, the calendar field value, and the calendar system. In addition,
get(f)
will not necessarily return value
set by
the call to the set
method
after the calendar 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 date 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 date 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 fieldf
before the call isdelta
, modulo any overflow that has occurred in fieldf
. 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 or other constraints, such as time zone offset changes, 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 thanDAY_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 thanHOUR
.
Example: See GregorianCalendar.roll(int, int)
.
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.
- Since:
- 1.1
- See Also:
-
Nested Class Summary
Modifier and TypeClassDescriptionstatic class
Calendar.Builder
is used for creating aCalendar
from various date-time parameters. -
Field Summary
Modifier and TypeFieldDescriptionstatic final int
A style specifier forgetDisplayNames
indicating names in all styles, such as "January" and "Jan".static final int
Value of theAM_PM
field indicating the period of the day from midnight to just before noon.static final int
Field number forget
andset
indicating whether theHOUR
is before or after noon.static final int
Value of theMONTH
field indicating the fourth month of the year in the Gregorian and Julian calendars.protected boolean
True iffields[]
are in sync with the currently set time.static final int
Value of theMONTH
field indicating the eighth month of the year in the Gregorian and Julian calendars.static final int
Field number forget
andset
indicating the day of the month.static final int
Field number forget
andset
indicating the day of the month.static final int
Field number forget
andset
indicating the day of the week.static final int
Field number forget
andset
indicating the ordinal number of the day of the week within the current month.static final int
Field number forget
andset
indicating the day number within the current year.static final int
Value of theMONTH
field indicating the twelfth month of the year in the Gregorian and Julian calendars.static final int
Field number forget
andset
indicating the daylight saving offset in milliseconds.static final int
Field number forget
andset
indicating the era, e.g., AD or BC in the Julian calendar.static final int
Value of theMONTH
field indicating the second month of the year in the Gregorian and Julian calendars.static final int
The number of distinct fields recognized byget
andset
.protected int[]
The calendar field values for the currently set time for this calendar.static final int
Value of theDAY_OF_WEEK
field indicating Friday.static final int
Field number forget
andset
indicating the hour of the morning or afternoon.static final int
Field number forget
andset
indicating the hour of the day.protected boolean[]
The flags which tell if a specified calendar field for the calendar is set.protected boolean
True if then the value oftime
is valid.static final int
Value of theMONTH
field indicating the first month of the year in the Gregorian and Julian calendars.static final int
Value of theMONTH
field indicating the seventh month of the year in the Gregorian and Julian calendars.static final int
Value of theMONTH
field indicating the sixth month of the year in the Gregorian and Julian calendars.static final int
static final int
A style specifier forgetDisplayName
andgetDisplayNames
indicating a long name used for format.static final int
A style specifier forgetDisplayName
andgetDisplayNames
indicating a long name used independently, such as a month name as calendar headers.static final int
Value of theMONTH
field indicating the third month of the year in the Gregorian and Julian calendars.static final int
Value of theMONTH
field indicating the fifth month of the year in the Gregorian and Julian calendars.static final int
Field number forget
andset
indicating the millisecond within the second.static final int
Field number forget
andset
indicating the minute within the hour.static final int
Value of theDAY_OF_WEEK
field indicating Monday.static final int
Field number forget
andset
indicating the month.static final int
A style specifier forgetDisplayName
andgetDisplayNames
indicating a narrow name used for format.static final int
A style specifier forgetDisplayName
andgetDisplayNames
indicating a narrow name independently.static final int
Value of theMONTH
field indicating the eleventh month of the year in the Gregorian and Julian calendars.static final int
Value of theMONTH
field indicating the tenth month of the year in the Gregorian and Julian calendars.static final int
Value of theAM_PM
field indicating the period of the day from noon to just before midnight.static final int
Value of theDAY_OF_WEEK
field indicating Saturday.static final int
Field number forget
andset
indicating the second within the minute.static final int
Value of theMONTH
field indicating the ninth month of the year in the Gregorian and Julian calendars.static final int
static final int
A style specifier forgetDisplayName
andgetDisplayNames
indicating a short name used for format.static final int
A style specifier forgetDisplayName
andgetDisplayNames
indicating a short name used independently, such as a month abbreviation as calendar headers.static final int
Value of theDAY_OF_WEEK
field indicating Sunday.static final int
Value of theDAY_OF_WEEK
field indicating Thursday.protected long
The currently set time for this calendar, expressed in milliseconds after January 1, 1970, 0:00:00 GMT.static final int
Value of theDAY_OF_WEEK
field indicating Tuesday.static final int
Value of theMONTH
field indicating the thirteenth month of the year.static final int
Value of theDAY_OF_WEEK
field indicating Wednesday.static final int
Field number forget
andset
indicating the week number within the current month.static final int
Field number forget
andset
indicating the week number within the current year.static final int
Field number forget
andset
indicating the year.static final int
Field number forget
andset
indicating the raw offset from GMT in milliseconds. -
Constructor Summary
-
Method Summary
Modifier and TypeMethodDescriptionabstract void
add
(int field, int amount) Adds or subtracts the specified amount of time to the given calendar field, based on the calendar's rules.boolean
Returns whether thisCalendar
represents a time after the time represented by the specifiedObject
.boolean
Returns whether thisCalendar
represents a time before the time represented by the specifiedObject
.final void
clear()
Sets all the calendar field values and the time value (millisecond offset from the Epoch) of thisCalendar
undefined.final void
clear
(int field) Sets the given calendar field value and the time value (millisecond offset from the Epoch) of thisCalendar
undefined.clone()
Creates and returns a copy of this object.int
Compares the time values (millisecond offsets from the Epoch) represented by twoCalendar
objects.protected void
complete()
Fills in any unset fields in the calendar fields.protected abstract void
protected abstract void
boolean
Compares thisCalendar
to the specifiedObject
.int
get
(int field) Returns the value of the given calendar field.int
getActualMaximum
(int field) Returns the maximum value that the specified calendar field could have, given the time value of thisCalendar
.int
getActualMinimum
(int field) Returns the minimum value that the specified calendar field could have, given the time value of thisCalendar
.Returns an unmodifiableSet
containing all calendar types supported byCalendar
in the runtime environment.static Locale[]
Returns an array of all locales for which thegetInstance
methods of this class can return localized instances.Returns the calendar type of thisCalendar
.getDisplayName
(int field, int style, Locale locale) Returns the string representation of the calendarfield
value in the givenstyle
andlocale
.getDisplayNames
(int field, int style, Locale locale) Returns aMap
containing all names of the calendarfield
in the givenstyle
andlocale
and their corresponding field values.int
Gets what the first day of the week is; e.g.,SUNDAY
in the U.S.,MONDAY
in France.abstract int
getGreatestMinimum
(int field) Returns the highest minimum value for the given calendar field of thisCalendar
instance.static Calendar
Gets a calendar using the default time zone and locale.static Calendar
getInstance
(Locale aLocale) Gets a calendar using the default time zone and specified locale.static Calendar
getInstance
(TimeZone zone) Gets a calendar using the specified time zone and default locale.static Calendar
getInstance
(TimeZone zone, Locale aLocale) Gets a calendar with the specified time zone and locale.abstract int
getLeastMaximum
(int field) Returns the lowest maximum value for the given calendar field of thisCalendar
instance.abstract int
getMaximum
(int field) Returns the maximum value for the given calendar field of thisCalendar
instance.int
Gets what the minimal days required in the first week of the year are; e.g., if the first week is defined as one that contains the first day of the first month of a year, this method returns 1.abstract int
getMinimum
(int field) Returns the minimum value for the given calendar field of thisCalendar
instance.final Date
getTime()
long
Returns this Calendar's time value in milliseconds.Gets the time zone.int
Returns the number of weeks in the week year represented by thisCalendar
.int
Returns the week year represented by thisCalendar
.int
hashCode()
Returns a hash code for this calendar.protected final int
internalGet
(int field) Returns the value of the given calendar field.boolean
Tells whether date/time interpretation is to be lenient.final boolean
isSet
(int field) Determines if the given calendar field has a value set, including cases that the value has been set by internal fields calculations triggered by aget
method call.boolean
Returns whether thisCalendar
supports week dates.abstract void
roll
(int field, boolean up) Adds or subtracts (up/down) a single unit of time on the given time field without changing larger fields.void
roll
(int field, int amount) Adds the specified (signed) amount to the specified calendar field without changing larger fields.void
set
(int field, int value) Sets the given calendar field to the given value.final void
set
(int year, int month, int date) Sets the values for the calendar fieldsYEAR
,MONTH
, andDAY_OF_MONTH
.final void
set
(int year, int month, int date, int hourOfDay, int minute) Sets the values for the calendar fieldsYEAR
,MONTH
,DAY_OF_MONTH
,HOUR_OF_DAY
, andMINUTE
.final void
set
(int year, int month, int date, int hourOfDay, int minute, int second) Sets the values for the fieldsYEAR
,MONTH
,DAY_OF_MONTH
,HOUR_OF_DAY
,MINUTE
, andSECOND
.void
setFirstDayOfWeek
(int value) Sets what the first day of the week is; e.g.,SUNDAY
in the U.S.,MONDAY
in France.void
setLenient
(boolean lenient) Specifies whether or not date/time interpretation is to be lenient.void
setMinimalDaysInFirstWeek
(int value) Sets what the minimal days required in the first week of the year are; For example, if the first week is defined as one that contains the first day of the first month of a year, call this method with value 1.final void
Sets this Calendar's time with the givenDate
.void
setTimeInMillis
(long millis) Sets this Calendar's current time from the given long value.void
setTimeZone
(TimeZone value) Sets the time zone with the given time zone value.void
setWeekDate
(int weekYear, int weekOfYear, int dayOfWeek) Sets the date of thisCalendar
with the given date specifiers - week year, week of year, and day of week.final Instant
Converts this object to anInstant
.toString()
Return a string representation of this calendar.
-
Field Details
-
ERA
public static final int ERAField number forget
andset
indicating the era, e.g., AD or BC in the Julian calendar. This is a calendar-specific value; see subclass documentation.- See Also:
-
YEAR
public static final int YEARField number forget
andset
indicating the year. This is a calendar-specific value; see subclass documentation.- See Also:
-
MONTH
public static final int MONTHField number forget
andset
indicating the month. This is a calendar-specific value. The first month of the year in the Gregorian and Julian calendars isJANUARY
which is 0; the last depends on the number of months in a year.- See Also:
-
WEEK_OF_YEAR
public static final int WEEK_OF_YEARField number forget
andset
indicating the week number within the current year. The first week of the year, as defined bygetFirstDayOfWeek()
andgetMinimalDaysInFirstWeek()
, has value 1. Subclasses define the value ofWEEK_OF_YEAR
for days before the first week of the year.- See Also:
-
WEEK_OF_MONTH
public static final int WEEK_OF_MONTHField number forget
andset
indicating the week number within the current month. The first week of the month, as defined bygetFirstDayOfWeek()
andgetMinimalDaysInFirstWeek()
, has value 1. Subclasses define the value ofWEEK_OF_MONTH
for days before the first week of the month.- See Also:
-
DATE
public static final int DATEField number forget
andset
indicating the day of the month. This is a synonym forDAY_OF_MONTH
. The first day of the month has value 1.- See Also:
-
DAY_OF_MONTH
public static final int DAY_OF_MONTHField number forget
andset
indicating the day of the month. This is a synonym forDATE
. The first day of the month has value 1.- See Also:
-
DAY_OF_YEAR
public static final int DAY_OF_YEARField number forget
andset
indicating the day number within the current year. The first day of the year has value 1.- See Also:
-
DAY_OF_WEEK
public static final int DAY_OF_WEEKField number forget
andset
indicating the day of the week. If the calendar is non-lenient, this field takes valuesSUNDAY
,MONDAY
,TUESDAY
,WEDNESDAY
,THURSDAY
,FRIDAY
, andSATURDAY
. Otherwise, any int values are accepted and normalized to one of the previously mentioned values.- See Also:
-
DAY_OF_WEEK_IN_MONTH
public static final int DAY_OF_WEEK_IN_MONTHField number forget
andset
indicating the ordinal number of the day of the week within the current month. Together with theDAY_OF_WEEK
field, this uniquely specifies a day within a month. UnlikeWEEK_OF_MONTH
andWEEK_OF_YEAR
, this field's value does not depend ongetFirstDayOfWeek()
orgetMinimalDaysInFirstWeek()
.DAY_OF_MONTH 1
through7
always correspond toDAY_OF_WEEK_IN_MONTH 1
;8
through14
correspond toDAY_OF_WEEK_IN_MONTH 2
, and so on.DAY_OF_WEEK_IN_MONTH 0
indicates the week beforeDAY_OF_WEEK_IN_MONTH 1
. Negative values count back from the end of the month, so the last Sunday of a month is specified asDAY_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 overlapDAY_OF_WEEK_IN_MONTH 5
and the end of4
.- See Also:
-
AM_PM
public static final int AM_PMField number forget
andset
indicating whether theHOUR
is before or after noon. E.g., at 10:04:15.250 PM theAM_PM
isPM
.- See Also:
-
HOUR
public static final int HOURField number forget
andset
indicating the hour of the morning or afternoon.HOUR
is used for the 12-hour clock (0 - 11). Noon and midnight are represented by 0, not by 12. E.g., at 10:04:15.250 PM theHOUR
is 10.- See Also:
-
HOUR_OF_DAY
public static final int HOUR_OF_DAYField number forget
andset
indicating the hour of the day.HOUR_OF_DAY
is used for the 24-hour clock. E.g., at 10:04:15.250 PM theHOUR_OF_DAY
is 22.- See Also:
-
MINUTE
public static final int MINUTEField number forget
andset
indicating the minute within the hour. E.g., at 10:04:15.250 PM theMINUTE
is 4.- See Also:
-
SECOND
public static final int SECONDField number forget
andset
indicating the second within the minute. E.g., at 10:04:15.250 PM theSECOND
is 15.- See Also:
-
MILLISECOND
public static final int MILLISECONDField number forget
andset
indicating the millisecond within the second. E.g., at 10:04:15.250 PM theMILLISECOND
is 250.- See Also:
-
ZONE_OFFSET
public static final int ZONE_OFFSETField number forget
andset
indicating the raw offset from GMT in milliseconds.This field reflects the correct GMT offset value of the time zone of this
Calendar
if theTimeZone
implementation subclass supports historical GMT offset changes.- See Also:
-
DST_OFFSET
public static final int DST_OFFSETField number forget
andset
indicating the daylight saving offset in milliseconds.This field reflects the correct daylight saving offset value of the time zone of this
Calendar
if theTimeZone
implementation subclass supports historical Daylight Saving Time schedule changes.- See Also:
-
FIELD_COUNT
public static final int FIELD_COUNTThe number of distinct fields recognized byget
andset
. Field numbers range from0..FIELD_COUNT-1
.- See Also:
-
SUNDAY
-
MONDAY
-
TUESDAY
-
WEDNESDAY
-
THURSDAY
-
FRIDAY
-
SATURDAY
-
JANUARY
public static final int JANUARYValue of theMONTH
field indicating the first month of the year in the Gregorian and Julian calendars.- See Also:
-
FEBRUARY
public static final int FEBRUARYValue of theMONTH
field indicating the second month of the year in the Gregorian and Julian calendars.- See Also:
-
MARCH
public static final int MARCHValue of theMONTH
field indicating the third month of the year in the Gregorian and Julian calendars.- See Also:
-
APRIL
public static final int APRILValue of theMONTH
field indicating the fourth month of the year in the Gregorian and Julian calendars.- See Also:
-
MAY
public static final int MAYValue of theMONTH
field indicating the fifth month of the year in the Gregorian and Julian calendars.- See Also:
-
JUNE
public static final int JUNEValue of theMONTH
field indicating the sixth month of the year in the Gregorian and Julian calendars.- See Also:
-
JULY
public static final int JULYValue of theMONTH
field indicating the seventh month of the year in the Gregorian and Julian calendars.- See Also:
-
AUGUST
public static final int AUGUSTValue of theMONTH
field indicating the eighth month of the year in the Gregorian and Julian calendars.- See Also:
-
SEPTEMBER
public static final int SEPTEMBERValue of theMONTH
field indicating the ninth month of the year in the Gregorian and Julian calendars.- See Also:
-
OCTOBER
public static final int OCTOBERValue of theMONTH
field indicating the tenth month of the year in the Gregorian and Julian calendars.- See Also:
-
NOVEMBER
public static final int NOVEMBERValue of theMONTH
field indicating the eleventh month of the year in the Gregorian and Julian calendars.- See Also:
-
DECEMBER
public static final int DECEMBERValue of theMONTH
field indicating the twelfth month of the year in the Gregorian and Julian calendars.- See Also:
-
UNDECIMBER
public static final int UNDECIMBERValue of theMONTH
field indicating the thirteenth month of the year. AlthoughGregorianCalendar
does not use this value, lunar calendars do.- See Also:
-
AM
public static final int AMValue of theAM_PM
field indicating the period of the day from midnight to just before noon.- See Also:
-
PM
public static final int PMValue of theAM_PM
field indicating the period of the day from noon to just before midnight.- See Also:
-
ALL_STYLES
public static final int ALL_STYLESA style specifier forgetDisplayNames
indicating names in all styles, such as "January" and "Jan".- Since:
- 1.6
- See Also:
-
SHORT
public static final int SHORT- Since:
- 1.6
- See Also:
-
LONG
public static final int LONG- Since:
- 1.6
- See Also:
-
NARROW_FORMAT
public static final int NARROW_FORMATA style specifier forgetDisplayName
andgetDisplayNames
indicating a narrow name used for format. Narrow names are typically single character strings, such as "M" for Monday.- Since:
- 1.8
- See Also:
-
NARROW_STANDALONE
public static final int NARROW_STANDALONEA style specifier forgetDisplayName
andgetDisplayNames
indicating a narrow name independently. Narrow names are typically single character strings, such as "M" for Monday.- Since:
- 1.8
- See Also:
-
SHORT_FORMAT
public static final int SHORT_FORMATA style specifier forgetDisplayName
andgetDisplayNames
indicating a short name used for format.- Since:
- 1.8
- See Also:
-
LONG_FORMAT
public static final int LONG_FORMATA style specifier forgetDisplayName
andgetDisplayNames
indicating a long name used for format.- Since:
- 1.8
- See Also:
-
SHORT_STANDALONE
public static final int SHORT_STANDALONEA style specifier forgetDisplayName
andgetDisplayNames
indicating a short name used independently, such as a month abbreviation as calendar headers.- Since:
- 1.8
- See Also:
-
LONG_STANDALONE
public static final int LONG_STANDALONEA style specifier forgetDisplayName
andgetDisplayNames
indicating a long name used independently, such as a month name as calendar headers.- Since:
- 1.8
- See Also:
-
fields
protected int[] fieldsThe calendar field values for the currently set time for this calendar. This is an array ofFIELD_COUNT
integers, with index valuesERA
throughDST_OFFSET
. -
isSet
protected boolean[] isSetThe flags which tell if a specified calendar field for the calendar is set. A new object has no fields set. After the first call to a method which generates the fields, they all remain set after that. This is an array ofFIELD_COUNT
booleans, with index valuesERA
throughDST_OFFSET
. -
time
protected long timeThe currently set time for this calendar, expressed in milliseconds after January 1, 1970, 0:00:00 GMT.- See Also:
-
isTimeSet
protected boolean isTimeSetTrue if then the value oftime
is valid. The time is made invalid by a change to an item offield[]
.- See Also:
-
areFieldsSet
protected boolean areFieldsSetTrue iffields[]
are in sync with the currently set time. If false, then the next attempt to get the value of a field will force a recomputation of all fields from the current value oftime
.
-
-
Constructor Details
-
Calendar
protected Calendar()Constructs a Calendar with the default time zone and the defaultFORMAT
locale.- See Also:
-
Calendar
-
-
Method Details
-
getInstance
Gets a calendar using the default time zone and locale. TheCalendar
returned is based on the current time in the default time zone with the defaultFORMAT
locale.If the locale contains the time zone with "tz" Unicode extension, that time zone is used instead.
- Returns:
- a Calendar.
-
getInstance
Gets a calendar using the specified time zone and default locale. TheCalendar
returned is based on the current time in the given time zone with the defaultFORMAT
locale.- Parameters:
zone
- the time zone to use- Returns:
- a Calendar.
- Throws:
NullPointerException
- ifzone
isnull
-
getInstance
Gets a calendar using the default time zone and specified locale. TheCalendar
returned is based on the current time in the default time zone with the given locale.If the locale contains the time zone with "tz" Unicode extension, that time zone is used instead.
- Parameters:
aLocale
- the locale for the week data- Returns:
- a Calendar.
- Throws:
NullPointerException
- ifaLocale
isnull
-
getInstance
Gets a calendar with the specified time zone and locale. TheCalendar
returned is based on the current time in the given time zone with the given locale.- Parameters:
zone
- the time zone to useaLocale
- the locale for the week data- Returns:
- a Calendar.
- Throws:
NullPointerException
- ifzone
oraLocale
isnull
-
getAvailableLocales
Returns an array of all locales for which thegetInstance
methods of this class can return localized instances. At a minimum, the returned array must contain aLocale
instance equal toLocale.ROOT
and aLocale
instance equal toLocale.US
.- Returns:
- An array of locales for which localized
Calendar
instances are available.
-
computeTime
-
computeFields
protected abstract void computeFields()Converts the current millisecond time valuetime
to calendar field values infields[]
. This allows you to sync up the calendar field values with a new time that is set for the calendar. The time is not recomputed first; to recompute the time, then the fields, call thecomplete()
method.- See Also:
-
getTime
-
setTime
Sets this Calendar's time with the givenDate
.Note: Calling
setTime()
withDate(Long.MAX_VALUE)
orDate(Long.MIN_VALUE)
may yield incorrect field values fromget()
.- Parameters:
date
- the given Date.- Throws:
NullPointerException
- ifdate
isnull
- See Also:
-
getTimeInMillis
public long getTimeInMillis()Returns this Calendar's time value in milliseconds.- Returns:
- the current time as UTC milliseconds from the epoch.
- See Also:
-
setTimeInMillis
public void setTimeInMillis(long millis) Sets this Calendar's current time from the given long value.- Parameters:
millis
- the new time in UTC milliseconds from the epoch.- See Also:
-
get
public int get(int field) Returns the value of the given calendar field. In lenient mode, all calendar fields are normalized. In non-lenient mode, all calendar fields are validated and this method throws an exception if any calendar fields have out-of-range values. The normalization and validation are handled by thecomplete()
method, which process is calendar system dependent.- Parameters:
field
- the given calendar field.- Returns:
- the value for the given calendar field.
- Throws:
IllegalArgumentException
- if thisCalendar
is non-lenient and any of the calendar fields have invalid values.- See Also:
-
internalGet
protected final int internalGet(int field) Returns the value of the given calendar field. This method does not involve normalization or validation of the field value.- Parameters:
field
- the given calendar field.- Returns:
- the value for the given calendar field.
- See Also:
-
set
public void set(int field, int value) Sets the given calendar field to the given value. The value is not interpreted by this method regardless of the leniency mode.- Parameters:
field
- the given calendar field.value
- the value to be set for the given calendar field.- See Also:
-
set
public final void set(int year, int month, int date) Sets the values for the calendar fieldsYEAR
,MONTH
, andDAY_OF_MONTH
. Previous values of other calendar fields are retained. If this is not desired, callclear()
first.- Parameters:
year
- the value used to set theYEAR
calendar field.month
- the value used to set theMONTH
calendar field. Month value is 0-based. e.g., 0 for January.date
- the value used to set theDAY_OF_MONTH
calendar field.- See Also:
-
set
public final void set(int year, int month, int date, int hourOfDay, int minute) Sets the values for the calendar fieldsYEAR
,MONTH
,DAY_OF_MONTH
,HOUR_OF_DAY
, andMINUTE
. Previous values of other fields are retained. If this is not desired, callclear()
first.- Parameters:
year
- the value used to set theYEAR
calendar field.month
- the value used to set theMONTH
calendar field. Month value is 0-based. e.g., 0 for January.date
- the value used to set theDAY_OF_MONTH
calendar field.hourOfDay
- the value used to set theHOUR_OF_DAY
calendar field.minute
- the value used to set theMINUTE
calendar field.- See Also:
-
set
public final void set(int year, int month, int date, int hourOfDay, int minute, int second) Sets the values for the fieldsYEAR
,MONTH
,DAY_OF_MONTH
,HOUR_OF_DAY
,MINUTE
, andSECOND
. Previous values of other fields are retained. If this is not desired, callclear()
first.- Parameters:
year
- the value used to set theYEAR
calendar field.month
- the value used to set theMONTH
calendar field. Month value is 0-based. e.g., 0 for January.date
- the value used to set theDAY_OF_MONTH
calendar field.hourOfDay
- the value used to set theHOUR_OF_DAY
calendar field.minute
- the value used to set theMINUTE
calendar field.second
- the value used to set theSECOND
calendar field.- See Also:
-
clear
public final void clear()Sets all the calendar field values and the time value (millisecond offset from the Epoch) of thisCalendar
undefined. This means thatisSet()
will returnfalse
for all the calendar fields, and the date and time calculations will treat the fields as if they had never been set. ACalendar
implementation class may use its specific default field values for date/time calculations. For example,GregorianCalendar
uses 1970 if theYEAR
field value is undefined.- See Also:
-
clear
public final void clear(int field) Sets the given calendar field value and the time value (millisecond offset from the Epoch) of thisCalendar
undefined. This means thatisSet(field)
will returnfalse
, and the date and time calculations will treat the field as if it had never been set. ACalendar
implementation class may use the field's specific default value for date and time calculations.The
HOUR_OF_DAY
,HOUR
andAM_PM
fields are handled independently and the the resolution rule for the time of day is applied. Clearing one of the fields doesn't reset the hour of day value of thisCalendar
. Useset(Calendar.HOUR_OF_DAY, 0)
to reset the hour value.- Parameters:
field
- the calendar field to be cleared.- See Also:
-
isSet
public final boolean isSet(int field) Determines if the given calendar field has a value set, including cases that the value has been set by internal fields calculations triggered by aget
method call.- Parameters:
field
- the calendar field to test- Returns:
true
if the given calendar field has a value set;false
otherwise.
-
getDisplayName
Returns the string representation of the calendarfield
value in the givenstyle
andlocale
. If no string representation is applicable,null
is returned. This method callsget(field)
to get the calendarfield
value if the string representation is applicable to the given calendarfield
.For example, if this
Calendar
is aGregorianCalendar
and its date is 2005-01-01, then the string representation of theMONTH
field would be "January" in the long style in an English locale or "Jan" in the short style. However, no string representation would be available for theDAY_OF_MONTH
field, and this method would returnnull
.The default implementation supports the calendar fields for which a
DateFormatSymbols
has names in the givenlocale
.If there is no string representation of the
Calendar
field
and the calendar is in non-lenient mode and any calendar fields have invalid values,null
is returned. If there is a string representation of theCalendar
field
and the calendar is in non-lenient mode and any calendar fields have invalid values,IllegalArgumentException
will be thrown.- Parameters:
field
- the calendar field for which the string representation is returnedstyle
- the style applied to the string representation; one ofSHORT_FORMAT
(SHORT
),SHORT_STANDALONE
,LONG_FORMAT
(LONG
),LONG_STANDALONE
,NARROW_FORMAT
, orNARROW_STANDALONE
.locale
- the locale for the string representation (any calendar types specified bylocale
are ignored)- Returns:
- the string representation of the given
field
in the givenstyle
, ornull
if no string representation is applicable. - Throws:
IllegalArgumentException
- iffield
orstyle
is invalid, or if thisCalendar
is non-lenient and any of the calendar fields have invalid valuesNullPointerException
- iflocale
is null- Since:
- 1.6
-
getDisplayNames
Returns aMap
containing all names of the calendarfield
in the givenstyle
andlocale
and their corresponding field values. For example, if thisCalendar
is aGregorianCalendar
, the returned map would contain "Jan" toJANUARY
, "Feb" toFEBRUARY
, and so on, in the short style in an English locale.Narrow names may not be unique due to use of single characters, such as "S" for Sunday and Saturday. In that case narrow names are not included in the returned
Map
.The values of other calendar fields may be taken into account to determine a set of display names. For example, if this
Calendar
is a lunisolar calendar system and the year value given by theYEAR
field has a leap month, this method would return month names containing the leap month name, and month names are mapped to their values specific for the year.The default implementation supports display names contained in a
DateFormatSymbols
. For example, iffield
isMONTH
andstyle
isALL_STYLES
, this method returns aMap
containing all strings returned byDateFormatSymbols.getShortMonths()
andDateFormatSymbols.getMonths()
.Unlike
getDisplayName(int, int, Locale)
, this method will not throw anIllegalArgumentException
if theCalendar
is non-lenient and any of the calendar fields have invalid values. Instead, this method will return eithernull
or aMap
.- Parameters:
field
- the calendar field for which the display names are returnedstyle
- the style applied to the string representation; one ofSHORT_FORMAT
(SHORT
),SHORT_STANDALONE
,LONG_FORMAT
(LONG
),LONG_STANDALONE
,NARROW_FORMAT
, orNARROW_STANDALONE
locale
- the locale for the display names- Returns:
- a
Map
containing all display names instyle
andlocale
and their field values, ornull
if no display names are defined forfield
- Throws:
IllegalArgumentException
- iffield
orstyle
is invalidNullPointerException
- iflocale
is null- Since:
- 1.6
-
complete
protected void complete()Fills in any unset fields in the calendar fields. First, thecomputeTime()
method is called if the time value (millisecond offset from the Epoch) has not been calculated from calendar field values. Then, thecomputeFields()
method is called to calculate all calendar field values. -
getAvailableCalendarTypes
Returns an unmodifiableSet
containing all calendar types supported byCalendar
in the runtime environment. The available calendar types can be used for the Unicode locale extensions. TheSet
returned contains at least"gregory"
. The calendar types don't include aliases, such as"gregorian"
for"gregory"
.- Returns:
- an unmodifiable
Set
containing all available calendar types - Since:
- 1.8
- See Also:
-
getCalendarType
Returns the calendar type of thisCalendar
. Calendar types are defined by the Unicode Locale Data Markup Language (LDML) specification.The default implementation of this method returns the class name of this
Calendar
instance. Any subclasses that implement LDML-defined calendar systems should override this method to return appropriate calendar types.- Returns:
- the LDML-defined calendar type or the class name of this
Calendar
instance - Since:
- 1.8
- See Also:
-
equals
Compares thisCalendar
to the specifiedObject
. The result istrue
if and only if the argument is aCalendar
object of the same calendar system that represents the same time value (millisecond offset from the Epoch) under the sameCalendar
parameters as this object.The
Calendar
parameters are the values represented by theisLenient
,getFirstDayOfWeek
,getMinimalDaysInFirstWeek
andgetTimeZone
methods. If there is any difference in those parameters between the twoCalendar
s, this method returnsfalse
.Use the
compareTo
method to compare only the time values. -
hashCode
-
before
Returns whether thisCalendar
represents a time before the time represented by the specifiedObject
. This method is equivalent to:
if and only ifcompareTo(when) < 0
when
is aCalendar
instance. Otherwise, the method returnsfalse
.- Parameters:
when
- theObject
to be compared- Returns:
true
if the time of thisCalendar
is before the time represented bywhen
;false
otherwise.- See Also:
-
after
Returns whether thisCalendar
represents a time after the time represented by the specifiedObject
. This method is equivalent to:
if and only ifcompareTo(when) > 0
when
is aCalendar
instance. Otherwise, the method returnsfalse
.- Parameters:
when
- theObject
to be compared- Returns:
true
if the time of thisCalendar
is after the time represented bywhen
;false
otherwise.- See Also:
-
compareTo
Compares the time values (millisecond offsets from the Epoch) represented by twoCalendar
objects.- Specified by:
compareTo
in interfaceComparable<Calendar>
- Parameters:
anotherCalendar
- theCalendar
to be compared.- Returns:
- the value
0
if the time represented by the argument is equal to the time represented by thisCalendar
; a value less than0
if the time of thisCalendar
is before the time represented by the argument; and a value greater than0
if the time of thisCalendar
is after the time represented by the argument. - Throws:
NullPointerException
- if the specifiedCalendar
isnull
.IllegalArgumentException
- if the time value of the specifiedCalendar
object can't be obtained due to any invalid calendar values.- Since:
- 1.5
-
add
public abstract void add(int field, int amount) Adds or subtracts the specified amount of time to the given calendar field, based on the calendar's rules. For example, to subtract 5 days from the current time of the calendar, you can achieve it by calling:add(Calendar.DAY_OF_MONTH, -5)
.- Parameters:
field
- the calendar field.amount
- the amount of date or time to be added to the field.- Throws:
IllegalArgumentException
- if thisCalendar
is non-lenient and any of the calendar fields have invalid values or iffield
isZONE_OFFSET
,DST_OFFSET
, or unknown.- See Also:
-
roll
public abstract void roll(int field, boolean up) Adds or subtracts (up/down) a single unit of time on the given time field without changing larger fields. For example, to roll the current date up by one day, you can achieve it by calling:roll(Calendar.DATE, true). When rolling on the year or Calendar.YEAR field, it will roll the year value in the range between 1 and the value returned by calling
getMaximum(Calendar.YEAR)
. When rolling on the month or Calendar.MONTH field, other fields like date might conflict and, need to be changed. For instance, rolling the month on the date 01/31/96 will result in 02/29/96. When rolling on the hour-in-day or Calendar.HOUR_OF_DAY field, it will roll the hour value in the range between 0 and 23, which is zero-based.- Parameters:
field
- the time field.up
- indicates if the value of the specified time field is to be rolled up or rolled down. Use true if rolling up, false otherwise.- Throws:
IllegalArgumentException
- if thisCalendar
is non-lenient and any of the calendar fields have invalid values or iffield
isZONE_OFFSET
,DST_OFFSET
, or unknown.- See Also:
-
roll
public void roll(int field, int amount) Adds the specified (signed) amount to the specified calendar field without changing larger fields. A negative amount means to roll down.NOTE: This default implementation on
Calendar
just repeatedly calls the version ofroll()
that rolls by one unit. This may not always do the right thing. For example, if theDAY_OF_MONTH
field is 31, rolling through February will leave it set to 28. TheGregorianCalendar
version of this function takes care of this problem. Other subclasses should also provide overrides of this function that do the right thing.- Parameters:
field
- the calendar field.amount
- the signed amount to add to the calendarfield
.- Throws:
IllegalArgumentException
- if thisCalendar
is non-lenient and any of the calendar fields have invalid values or iffield
isZONE_OFFSET
,DST_OFFSET
, or unknown.- Since:
- 1.2
- See Also:
-
setTimeZone
Sets the time zone with the given time zone value.- Parameters:
value
- the given time zone.
-
getTimeZone
Gets the time zone.- Returns:
- the time zone object associated with this calendar.
-
setLenient
public void setLenient(boolean lenient) Specifies whether or not date/time interpretation is to be lenient. With lenient interpretation, a date such as "February 942, 1996" will be treated as being equivalent to the 941st day after February 1, 1996. With strict (non-lenient) interpretation, such dates will cause an exception to be thrown. The default is lenient.- Parameters:
lenient
-true
if the lenient mode is to be turned on;false
if it is to be turned off.- See Also:
-
isLenient
public boolean isLenient()Tells whether date/time interpretation is to be lenient.- Returns:
true
if the interpretation mode of this calendar is lenient;false
otherwise.- See Also:
-
setFirstDayOfWeek
public void setFirstDayOfWeek(int value) Sets what the first day of the week is; e.g.,SUNDAY
in the U.S.,MONDAY
in France.- Parameters:
value
- the given first day of the week.- See Also:
-
getFirstDayOfWeek
public int getFirstDayOfWeek()Gets what the first day of the week is; e.g.,SUNDAY
in the U.S.,MONDAY
in France.- Returns:
- the first day of the week.
- See Also:
-
setMinimalDaysInFirstWeek
public void setMinimalDaysInFirstWeek(int value) Sets what the minimal days required in the first week of the year are; For example, if the first week is defined as one that contains the first day of the first month of a year, call this method with value 1. If it must be a full week, use value 7.- Parameters:
value
- the given minimal days required in the first week of the year.- See Also:
-
getMinimalDaysInFirstWeek
public int getMinimalDaysInFirstWeek()Gets what the minimal days required in the first week of the year are; e.g., if the first week is defined as one that contains the first day of the first month of a year, this method returns 1. If the minimal days required must be a full week, this method returns 7.- Returns:
- the minimal days required in the first week of the year.
- See Also:
-
isWeekDateSupported
public boolean isWeekDateSupported()Returns whether thisCalendar
supports week dates.The default implementation of this method returns
false
.- Returns:
true
if thisCalendar
supports week dates;false
otherwise.- Since:
- 1.7
- See Also:
-
getWeekYear
public int getWeekYear()Returns the week year represented by thisCalendar
. The week year is in sync with the week cycle. The first day of the first week is the first day of the week year.The default implementation of this method throws an
UnsupportedOperationException
.- Returns:
- the week year of this
Calendar
- Throws:
UnsupportedOperationException
- if any week year numbering isn't supported in thisCalendar
.- Since:
- 1.7
- See Also:
-
setWeekDate
public void setWeekDate(int weekYear, int weekOfYear, int dayOfWeek) Sets the date of thisCalendar
with the given date specifiers - week year, week of year, and day of week.Unlike the
set
method, all of the calendar fields andtime
values are calculated upon return.If
weekOfYear
is out of the valid week-of-year range inweekYear
, theweekYear
andweekOfYear
values are adjusted in lenient mode, or anIllegalArgumentException
is thrown in non-lenient mode.The default implementation of this method throws an
UnsupportedOperationException
.- Parameters:
weekYear
- the week yearweekOfYear
- the week number based onweekYear
dayOfWeek
- the day of week value: one of the constants for theDAY_OF_WEEK
field:SUNDAY
, ...,SATURDAY
.- Throws:
IllegalArgumentException
- if any of the given date specifiers is invalid or any of the calendar fields are inconsistent with the given date specifiers in non-lenient modeUnsupportedOperationException
- if any week year numbering isn't supported in thisCalendar
.- Since:
- 1.7
- See Also:
-
getWeeksInWeekYear
public int getWeeksInWeekYear()Returns the number of weeks in the week year represented by thisCalendar
.The default implementation of this method throws an
UnsupportedOperationException
.- Returns:
- the number of weeks in the week year.
- Throws:
UnsupportedOperationException
- if any week year numbering isn't supported in thisCalendar
.- Since:
- 1.7
- See Also:
-
getMinimum
public abstract int getMinimum(int field) Returns the minimum value for the given calendar field of thisCalendar
instance. The minimum value is defined as the smallest value returned by theget
method for any possible time value. The minimum value depends on calendar system specific parameters of the instance.- Parameters:
field
- the calendar field.- Returns:
- the minimum value for the given calendar field.
- See Also:
-
getMaximum
public abstract int getMaximum(int field) Returns the maximum value for the given calendar field of thisCalendar
instance. The maximum value is defined as the largest value returned by theget
method for any possible time value. The maximum value depends on calendar system specific parameters of the instance.- Parameters:
field
- the calendar field.- Returns:
- the maximum value for the given calendar field.
- See Also:
-
getGreatestMinimum
public abstract int getGreatestMinimum(int field) Returns the highest minimum value for the given calendar field of thisCalendar
instance. The highest minimum value is defined as the largest value returned bygetActualMinimum(int)
for any possible time value. The greatest minimum value depends on calendar system specific parameters of the instance.- Parameters:
field
- the calendar field.- Returns:
- the highest minimum value for the given calendar field.
- See Also:
-
getLeastMaximum
public abstract int getLeastMaximum(int field) Returns the lowest maximum value for the given calendar field of thisCalendar
instance. The lowest maximum value is defined as the smallest value returned bygetActualMaximum(int)
for any possible time value. The least maximum value depends on calendar system specific parameters of the instance. For example, aCalendar
for the Gregorian calendar system returns 28 for theDAY_OF_MONTH
field, because the 28th is the last day of the shortest month of this calendar, February in a common year.- Parameters:
field
- the calendar field.- Returns:
- the lowest maximum value for the given calendar field.
- See Also:
-
getActualMinimum
public int getActualMinimum(int field) Returns the minimum value that the specified calendar field could have, given the time value of thisCalendar
.The default implementation of this method uses an iterative algorithm to determine the actual minimum value for the calendar field. Subclasses should, if possible, override this with a more efficient implementation - in many cases, they can simply return
getMinimum()
.- Parameters:
field
- the calendar field- Returns:
- the minimum of the given calendar field for the time
value of this
Calendar
- Since:
- 1.2
- See Also:
-
getActualMaximum
public int getActualMaximum(int field) Returns the maximum value that the specified calendar field could have, given the time value of thisCalendar
. For example, the actual maximum value of theMONTH
field is 12 in some years, and 13 in other years in the Hebrew calendar system.The default implementation of this method uses an iterative algorithm to determine the actual maximum value for the calendar field. Subclasses should, if possible, override this with a more efficient implementation.
- Parameters:
field
- the calendar field- Returns:
- the maximum of the given calendar field for the time
value of this
Calendar
- Since:
- 1.2
- See Also:
-
clone
-
toString
Return a string representation of this calendar. This method is intended to be used only for debugging purposes, and the format of the returned string may vary between implementations. The returned string may be empty but may not benull
. -
toInstant
-