PHP offers a powerful way to convert dates from one calendar system to another. In order
to do this, you must first convert a date into a Julian Day Count. You then convert that
integer back into a date according to another calendar.
These functions require the calendar extension. You may load it dynamically, or compile
it into PHP.
integer easter_date(integer year)
Use easter_date to get the timestamp for midnight on Easter for a given year.
<?
print(easter_date(2000));
?>
integer easter_days(integer year)
The easter_days function returns the number of days after March 21 on which Easter
falls for the given year.
<?
print(easter_days(2000));
?>
integer frenchtojd(integer month, integer day, integer year)
The frenchtojd function returns the Julian Day Count for the given French Republican
calendar date.
<?
$jdc = frenchtojd(1,1,1);
print(jdtogregorian($jdc));
?>
integer gregoriantojd(integer month, integer day, integer year)
The gregoriantojd function returns the Julian Day Count for the given Gregorian date.
<?
$jdc = gregoriantojd(1,1,1);
print(jdtogregorian($jdc));