Here is one way using Date::Calc: 
    #!/usr/bin/perl -wl

    use strict;

    use Date::Calc 'Nth_Weekday_of_Month_Year';


    sub max_days_in_month {

        my $day   = $_[0]; # Monday  is 1
        my $month = $_[1]; # January is 1
        my $year  = $_[2];

        scalar grep {Nth_Weekday_of_Month_Year($year, $month, $day, $_
+)} 1..5;
    } 


    print "There are ", max_days_in_month(1, 6, 2002), " Mondays in Ju
+ne 2002.";
    print "There are ", max_days_in_month(6, 6, 2002), " Sundays in Ju
+ne 2002.";

    __END__
    Prints:

    There are 4 Mondays in June 2002.
    There are 5 Sundays in June 2002.

    (Good news for those for prefer Sundays to Mondays)

[download]

--
John.

In reply to Re: Counting number of a particular day of the month. by jmcnamara
in thread Counting number of a particular day of the month. by ninja-joe

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.