I've got several scripts which rely on previous calendar dates. Not just yesterday, but possibly 60, 30, etc days in the past. A typical example would be to fill a hash with the caledar dates for the past 45 days. I wrote a subrouting which works fine. If I want a date other that yesterday, I just loop through the routine for the desired number of days. Is there a module which handles this type of date calculation easily? Or a standard way of handling this in Perl? I'm just looking for input.

My subroutine accepts a date such as 2005-03-01, and returns the previous date, similarly formatted. 

sub get_yesterday {
   my $date = shift;
   my ($year, $month, $day) = split/-/,$date;
   $month--;

   my @days_per_month = qw(31 28 31 30 31 30 31 31 30 31 30 31);

   if (($year %  4 == 0 && $year % 100 != 0) || $year % 400 == 0) {
      $days_per_month[1] = '29';
   }

   if ($day == 1) {
      if ($month == 0) {
         $month = '11';
         $year--;
      } else {
         $month--;
      }
      $day = $days_per_month[$month];
   } else {
      $day--;
   }
   $month++;
   for ($year, $month, $day) {
      if (/\b\d{1}\b/) {
         $_ = "0$_";
      }
   }
   return "$year-$month-$day";
}

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In reply to Getting yesterday's date, and random dates in the past by mhearse

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