Question

I have two Perl string variables containing date values. I want to check whether str1 variable date value is 1 day before the str2 value. How can i check it? if it doesn’t have 1 day before str2 then i need to print an error message.

 $str1="20120704"
 $str2="20120705

Answer 1

Use the standard Time::Piece module

#!/usr/bin/perl

use strict;
use warnings;
use 5.010;

use Time::Piece;

my $format = '%Y%m%d';

while (<DATA>) {
  chomp;
  my ($str1, $str2) = split;

  my $dt1 = Time::Piece->strptime($str1, $format);
  my $dt2 = Time::Piece->strptime($str2, $format);

  print "$str1 / $str2: ";
  if ($dt2->julian_day - $dt1->julian_day == 1) {
    say "ok";
  } else {
    say "not ok";
  }
}

__END__
20120704 20120705
20120630 20120701