We have one funding source with strange rounding rules for hour-long units. Anything between 8-90 mins rounds to 1 unit, 91-150 mins rounds to 2 units, 151-210 rounds to 3 units, etc. Without a custom rounding rule, we have to manually edit any appointments that are over one hour in duration so that we are not overbilling units, but also can bill appointments between 8-30 mins in duration.