
 Date::Calc  Gregorian calendar date calculations  search.cpan.org 
  This package consists of a C library and a Perl module (which uses the C library, internally) for all kinds of date calculations based on the Gregorian calendar (the one used in all western countries today), thereby complying with all relevant norms and standards: ISO/R 20151971, DIN 1355 and, to some extent, ISO 8601 (where applicable). 
  Second, it can be used to convert the canonical representation of a date, i.e., the number of that day (where counting starts at the 1st of January in 1 A.D.), back into a date given as year, month and day. 
  This function converts a date into a time value, i.e., into the number of seconds since whatever moment in time your system considers to be the "epoch";. 
 search.cpan.org /dist/DateCalc/Calc.pod (9766 words) 
