> perl -Mwarnings -Mstrict -le 'my $x = "2005-01-21"; my $y = "2005-01-22"; print($x <=> $y);'
Argument "2005-01-22" isn't numeric in numeric comparison (<=>) at -e line 1.
Argument "2005-01-21" isn't numeric in numeric comparison (<=>) at -e line 1.
0