Is that how you're supposed to do it? All my life I've been subtracting 2 and ignoring the fist digit for PM times (with the exception of post 20:00 times). I just noticed that when I was a kid and been using that all this time
e.g. 17:00 - 2:00 = 15:00 => 5:00
Which is the same as subtracting 12 (subtracting 2 and then subtracting 10, which is what ignoring the first digit does for times before 20:00).
22:00 - 2:00 = 20:00 => 0:00
Is that how you're supposed to do it? All my life I've been subtracting 2 and ignoring the fist digit for PM times (with the exception of post 20:00 times). I just noticed that when I was a kid and been using that all this time
e.g. 17:00 - 2:00 = 15:00 => 5:00