It is not legal in Colorado, anyway, to bank hours.
(BTW, Aline I was referring to the original post not your post.)
Here was the situation.

It drove my partner nuts that guy's would turn in 44 hours one week and turn in 36 hours the next week causing O.T. pay one week and leaving us short handed the next. We ran on a two week pay period so he would average it for an 80 hour pay period in the above example and not pay the O.T. for the first week. Not legal.

My guy's would often ask if they could comp their time for their own benefit and work extra hours one week so they could take off work, say, early the next Friday. I would agree but insisted that they leveled the time card to show 40/40 and apply the time to the appropriate job...... That is not legal either but I did not know it at the time.

There are a million ways to provide incentive for quality work but I don't think messing with hours is the way to do it.