This is a set of routines designed to make any common
       date/time manipulation easy to do.  Operations such as
       comparing two times, calculating a time a given amount of
       time from another, or parsing international times are all
       easily done.

       Date::Manip deals only with the Gregorian calendar (the
       one currently in use).  The Julian calendar defined leap
       years as every 4th year.  The Gregorian calendar improved
       this by making every 100th year NOT a leap year, unless it
       was also the 400th year.  The Gregorian calendar has been
       extrapolated back to the year 1000 AD and forward to the
       year 9999 AD.  Note that in historical context, the Julian
       calendar was in use until 1582 when the Gregorian calendar
       was adopted by the Catholic church.  Protestant countries
       did not accept it until later; Germany and Netherlands in
       1698, British Empire in 1752, Russia in 1918.  Note that
       the Gregorian calendar is itself imperfect.  Each year is
       on average 26 seconds too long, which means that every
       3,323 years, a day should be removed from the calendar.
       No attempt is made to correct for that.

       Date::Manip is therefore not equipped to truly deal with
       historical dates, but should be able to perform
       (virtually) any operation dealing with a modern time and
       date.

       Among other things, Date::Manip allow you to:

       1.  Enter a date and be able to choose any format
           convenient

       2.  Compare two dates, entered in widely different formats
           to determine which is earlier

       3.  Extract any information you want from ANY date using a
           format string similar to the Unix date command

       4.  Determine the amount of time between two dates

       5.  Add a time offset to a date to get a second date (i.e.
           determine the date 132 days ago or 2 years and 3 months
           after Jan 2, 1992)

       6.  Work with dates with dates using international formats
           (foreign month names, 12-10-95 referring to October rather than
           December, etc.).

       Each of these tasks is trivial (one or two lines at most)
       with this package.

       Although the word date is used extensively here, it is
       actually somewhat misleading.  Date::Manip works with the
       full date AND time (year, month, day, hour, minute,
       second).

WWW: http://www.cise.ufl.edu/~sbeck/