Doing day math with %j which is day of year (yday)

#!/usr/bin/perl --
## perltidy -olq  -csc -csci=10 -cscl="sub : BEGIN END" -otr -opr -ce 
+-nibc -i=4 -pt=0   "-nsak=*"
use strict;
use warnings;
use Time::Piece;
my $now = localtime;
my $year = shift || $now->year;

for my $mon ( 1 .. 12 ) {
    my $first = Time::Piece->strptime( qq/$year-$mon/, q/%Y-%m/ );
    my $mon   = $first->mon;
    my $yday  = $first->yday;
    my( $last ) =
      grep { $_->mon == $mon }
      map { Time::Piece->strptime( qq/$year-$_/, q/%Y-%j/ ) }
      map { $yday + $_ } reverse 28 .. 31;

    printf '%4d %3s %02d/%02d-%02d/%02d  ',
      $first->year, $first->month,
      $first->mon,  $first->mday,
      $last->mon,   $last->mday,;
    print "\n" if 0 == $mon % 3;
}
__END__
2013 Jan 01/01-01/31  2013 Feb 02/01-02/28  2013 Mar 03/01-03/31  
2013 Apr 04/01-04/30  2013 May 05/01-05/31  2013 Jun 06/01-06/30  
2013 Jul 07/01-07/31  2013 Aug 08/01-08/31  2013 Sep 09/01-09/30  
2013 Oct 10/01-10/31  2013 Nov 11/01-11/30  2013 Dec 12/01-12/31

[download]

In reply to Re^2: How to find first day of the first week on the month? ( strptime %Y-%j time-piece-firstlastofeverymonth.pl) by Anonymous Monk
in thread How to find first day of the first week on the month? by devbond

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