PHP Calendar Functions

The calendar functions are useful when working with different calendar formats. The standard it is based on is the Julian day count (Julian day count is a count of days starting from January 1, 4713 B.C.). Note that the Julian day count is not the same as the Julian calendar!
Note: To convert between calendar formats, you must first convert to Julian day count, then to the calendar format.

Installation

The windows version of PHP has built-in support for the calendar extension. So, the calendar functions will work automatically.
However, if you are running the Linux version of PHP, you will have to compile PHP with --enable-calendar to get the calendar functions to work.


PHP Calendar Functions

PHP: indicates the earliest version of PHP that supports the function.

Function Description PHP
cal_days_in_month() Returns the number of days in a month for a specified year and calendar 4
cal_from_jd()Converts a Julian day count into a date of a specified calendar4
cal_info()

Returns information about a given calendar
4
cal_to_jd()Converts a date to Julian day count4
easter_date()Returns the Unix timestamp for midnight on Easter of a specified year3
easter_days()Returns the number of days after March 21, on which Easter falls for a specified year3
FrenchToJD()Converts a French Republican date to a Julian day count3
GregorianToJD()Converts a Gregorian date to a Julian day count3
JDDayOfWeek()

Returns the day of a week
3
JDMonthName()Returns a month name3
JDToFrench()
Converts a Julian day count to a French Republican date
3
JDToGregorian()Converts a Julian day count to a Gregorian date3
jdtojewish()Converts a Julian day count to a Jewish date3
JDToJulian()Converts a Julian day count to a Julian date3
jdtounix()Converts a Julian day count to a Unix timestamp4
JewishToJD()

Converts a Jewish date to a Julian day count
3
JulianToJD()

Converts a Julian date to a Julian day count
3
unixtojd()

Converts a Unix timestamp to a Julian day count
4



PHP Calendar Constants

PHP: indicates the earliest version of PHP that supports the constant.

Constant Description PHP
CAL_GREGORIAN Gregorian calendar 3
CAL_JULIAN Julian calendar 3
CAL_JEWISH Jewish calendar 3
CAL_FRENCH French Republican calendar 3
CAL_NUM_CALS 3
CAL_DOW_DAYNO 3
CAL_DOW_SHORT 3
CAL_DOW_LONG 3
CAL_MONTH_GREGORIAN_SHORT 3
CAL_MONTH_GREGORIAN_LONG 3
CAL_MONTH_JULIAN_SHORT 3
CAL_MONTH_JULIAN_LONG 3
CAL_MONTH_JEWISH 3
CAL_MONTH_FRENCH 3
CAL_EASTER_DEFAULT 4
CAL_EASTER_ROMAN 4
CAL_EASTER_ALWAYS_GREGORIAN 4
CAL_EASTER_ALWAYS_JULIAN 4
CAL_JEWISH_ADD_ALAFIM_GERESH 5
CAL_JEWISH_ADD_ALAFIM 5
CAL_JEWISH_ADD_GERESHAYIM 5