PEAR generic classes for representation and manipulation of dates,
times and time zones without the need of timestamps, which is a
huge limitation for php programs. Includes time zone data, time
zone conversions and many date/time conversions.

It does not rely on 32-bit system date stamps, so you can display
calendars and compare dates that date pre 1970 and post 2038. This
package also provides a class to convert date strings between
Gregorian and Human calendar formats.

WWW: http://pear.php.net/package/Date