use Date::Calc 'Add_Delta_YM';

my $date_limit = sprintf( '%02d-%02d-%04d',
    reverse               # Y M D --> D M Y
    Add_Delta_YM(
        sub {
            $_[5] + 1900, # year
            $_[4] +    1, # month
            $_[3],        # and day
                       0, # less this many years
                     -13, # and this many months
        }->(localtime),   # from today
    )
);