I think the '+ 0' trick to force a numeric value is unnecessary here. It looks like '==' already does that for you. (of course your second suggestion is better than either of these, but still...)

#!/usr/bin/perl -wT
use strict;

my @vals = ('07','7',07,7,8);

# eq tests
for my $month (@vals) {
  print $month, $month eq 7 ? ' eq' : ' !eq', " 7\n";
}
print "\n";

# == tests
for my $month (@vals) {
  print $month, $month == 7 ? ' ==' : ' !==', " 7\n";
}
print "\n";

=OUTPUT
07 !eq 7
 7  eq 7
 7  eq 7
 7  eq 7
 8 !eq 7

07  == 7
 7  == 7
 7  == 7
 7  == 7
 8 !== 7
[download]

-Blake