Here is a solution also using Date::Calc. 
#!/usr/bin/perl
use strict;
use warnings;
use 5.014;
use Date::Calc qw( Delta_Days Days_in_Month );

while (<DATA>) {
    my ($y1, $m1, $d1, $y2, $m2, $d2) = split /\D+/;
    $y2 ||= $y1;
    $m2 ||= $m1;
    $d2 ||= Days_in_Month($y2, $m2); # last day in current month
    say Delta_Days($y1, $m1, $d1, $y2, $m2, $d2);
}

[download]

In reply to Re: Trouble with Dates by Cristoforo
in thread Trouble with Dates by rruser

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.