Hi, @anton2demin.

12:31am is 31 minutes past midnight. 10:31 am is 10 hours later, i.e. 600 minutes.
I’m not sure why the result isn’t -600 minutes but it’s probably that you’re displaying the number without a minus sign.

12:31pm minus 10:30am would give you a difference of 120 minutes or 2 hours.