@Ray: I don’t think that is the issue, I managed to test case B last night and it worked same as case A. So it started at around 20:40 and it was supposed to end around 5:40am, but it didn’t, it was scheduled to run for about 14 hours in both cases even if the preview was displaying correctly.
Sunrise hour is working great with another program of sprinkler where I set up to start it at Sunrise +1h and it is working for a week correctly.
My guess is this: When the schedule is computed to run between 20:40 and 5:40 means about 9h so when it starts it adds some values from the next day cycle because is going to next day. So 9h + 3 hours and 20 minutes from the next day evening. Just a guess.