or download this
my $day1_prog1_start = Date_to_Time(2007, 8, 8, 17, 0, 0);
my $day1_prog2_start = Date_to_Time(2007, 8, 8, 23, 0, 0);
...
print("If Prog1 starts at $next_prog1_start_str,\n");
print("Prog2 will likely start at $next_prog2_start_str.\n");