+ # If the time is 12:00-23:59, move to the next day by adding 18
+ # hours to $mnow. Because of DST this can end up from 05:00 to 18:59
+ # but it's always within the next day.
+ $mnow += 64800 if $hour >= 12;
+ # Get the new day, month, and year.
+ ($mday,$mon,$year) = (localtime($mnow))[3..5];
+ # Then set $mnow to midnight on that date.