G'day derekstucki,

Your main problem is that "my $age = (localtime ( time - $time ))[5];" is not doing what you presumable imagine it does. Consider the following which assumes an age of 25:

$ perl -Mstrict -Mwarnings -E '
    my $x = time; say $x;
    my $y = int($x - (25*365.24225*24*60*60)); say $y;
    my $z = (localtime($x-$y))[5]; say $z
'
1389999563
601076303
95
[download]

That's out by 70. Using ages of 5 and 45 gives 75 and 115 respectively: i.e. out by 70 also. You added the comment "# localtime returns years since 1900": you took this into consideration with your first localtime() (i.e. ... + 1900) but ignored it with the second. The epoch started in 1970: that's 70 years since 1900. Had you added 1900 for $age, then substracted 1970, you would have got the right answer: obviously that's ridiculously complicated. Here's a much easier way to do it:

#!/usr/bin/env perl -l

use strict;
use warnings;

use Time::Piece;
use Time::Seconds;

my @YMDs = ([2004, 1, 17], [2004, 1, 18], [2004, 1, 19]);
my $now = localtime;
print 'Now: ', $now->strftime('%Y-%m-%d');

for (@YMDs) {
    my $dob = Time::Piece->strptime(join('-' => @$_), '%Y-%m-%d');
    print 'DOB: ', $dob->strftime('%Y-%m-%d');
    print 'Age: ', int(($now->epoch - $dob->epoch) / ONE_YEAR);
}
[download]

Output:

Now: 2014-01-18
DOB: 2004-01-17
Age: 10
DOB: 2004-01-18
Age: 10
DOB: 2004-01-19
Age: 9
[download]

You also have problems in your regex:

• You don't need to escape forward slashes in character classes: see perlrecharclass: Special Characters Inside a Bracketed Character Class.
• A hyphen between two characters in a character class creates a range; '[ -\/]' matches the 16 characters between a space and a forward slash inclusive: see perlrecharclass: Character Ranges.
• '[ -\/\\]+' (in two places) matches one or more times; I suspect you actually want to match exactly one time.

You also have problems in your validation (if( $mon < 0 or ...); for instance, 31st February would be considered valid!