Is this calculation correct?

[flowerpot1000000]

Im owened 12 hours 40mins by a company they paid me to 20 hours so I now owe them back 7 hours - is this correct?

Anyone, Ive done it 3 times and go different answers!

20 hours minus 12 hours and 40 minutes is 7 hours and 20 minutes - I think that's what you wanted to calculate?

How granular does your workplace measure time? 20 hours less 12 hour 40 mins = 7 hours 20 mins.

Yes that's the one IVe re-done it and I owe 7 hours 20mins back to the company

You make no sense, but 20 hours minus 12 hours and 40 minutes = 7 hours and 20 mins. That's really not a hard calculation...