Television networks whose run times are off the hour. The other day I recorded a TV episode I'd not previously seen and the recording stopped 10 seconds short of the end of the episode.
I actually stopped watching several free-to-air stations some years ago, because they weren't just 10 seconds off the hour, but 10-20 minutes. Program to run 8:30 to 9:30? Yup, it would start around 8:45 and finish around 9:50. The program guides had the times down as the half-hours, my clocks were right (I checked), and yet, persistently, I'd allow an extra 10-15 minutes at the end of the program and still miss recording it all.
I think it started as a network strategy to keep viewers on that station. So, if what you're watching finishes 5 minutes later than the half-hour, then what you may want to watch on the opposition network has already started, so if you've missed the beginning, you'll stay where you are. Then several networks started doing it. Grrrr.
No idea what they're like now, because I never watch them any more, and most things I want to see on the satellite paid network I record anyway.