Rounding hours

My company recently switched to a new clocking program, during a transition phase where we have been using both the new and old we noticed some differences, the biggest being the rounding. My employer pays on the tenth of an hour, so it rounds to numbers divisible by 6. The issue here being that it seems to ALWAYS round in the employer favor, for example, If I punch in at 10:01 it rounds me to clock in at 10:06 (losing 5 mins) then if I were to clock out at 6:01 it rounds me to 6:00 (losing another minute). The biggest part I noticed was when I punched at 6:17, thinking it would round it 6:18, it rounded me down to 6:12 losing 5 mins in one punch. Give our mandatory lunch breaks that leaves the potential to lose 5 mins per punch, up to 20 mins a day! Over an hour a week! Is this legal?

Even weirder yet there are some rounding issues we can't even figure out, example a close co-worker of mine worked from 2:56 to 7:56 after his lunch (total of five hours) and his time clock shows 2:56 to 7:56 then says hours paid as 4.8 so .20 off would be a total of 12 mins on something OBVIOUSLY a straight 5 hours, even rounding in any manner we couldn't figure out the method on this one and our employer has given us no answers as far as how it rounds aside from it goes to the nearest tenth (which obviously isn't the case)