#  Inputs:  $1 ... date 1, as a timet
#           $2 ... date 2, as a timet
#
# Outputs:  $1 ... nonzero if the dates match, ignoring the actual times
#                  of day for each, zero if they are different.
#
sub same_date {
    my ($timestamp1, $timestamp2) = @_;
    my ($day1, $month1, $year1) = (localtime $timestamp1)[3,4,5];
    my ($day2, $month2, $year2) = (localtime $timestamp2)[3,4,5];
    return ($day1 == $day2 && $month1 == $month2 && $year1 == $year2);
}