# input:
chomp(my $date = <>);
# parse, return numeric year,month,day or empty list on error
if (my ($y,$m,$d) = split_date($date)) {
  # print out in Month dd yy format
  print "Date is: ", format_date($y,$m,$d), "\n";
} else {
  print "invalid date: $date; please try again\n";
}