The PHP cal_days_in_month() function returns the number of days in a month for a specified year and calendar.

The PHP cal_from_jd() function converts a Julian Day Count into a date of a specified calendar.

The PHP cal_info() function returns information about a specified calendar, or all calendars If the calendar parameter is omitted.

The PHP cal_to_jd() function converts a date in a specified calendar to Julian Day Count.

The PHP easter_date() function returns the Unix timestamp for midnight on Easter of the current year, or a given year if specified.

The PHP easter_days() function returns the number of days after March 21, that the Easter Day is in the current year, or a given year if specified.

The PHP frenchtojd() function converts a date from the French Republican Calendar (used by the French for twelve years from 1793) to a Julian Day Count.

The PHP gregoriantojd() function converts a date from the Gregorian Calendar to a Julian Day Count.

The PHP jddayofweek() function returns the day of the week.

The PHP jdmonthname() function returns a month name.

The PHP jdtofrench() function converts a Julian Day Count to a French Republican date (used by the French for twelve years from 1793).

The PHP jdtogregorian() function converts a Julian Day Count to a Gregorian date.

The PHP jdtojewish() function converts a Julian Day Count to a Jewish date.

The PHP jdtojulian() function converts a Julian Day Count to a Julian date.

The PHP jdtounix() function converts the Julian Day Count to a Unix timestamp.

The PHP jewishtojd() function converts a date from the Jewish Calendar to a Julian Day Count.

The PHP juliantojd() function converts a date from the Julian Calendar to a Julian Day Count.

The PHP unixtojd() function converts a Unix timestamp (the number of seconds since midnight of January 1, 1970) to a Julian Day Count.