There is always a fudge factor with timesheets.

To pretend it's not there is to lower yourself to the level of a criminal.

I guess you can constantly make notes as to what time it is as you multitask at work to get around this problem, but who really does that? Most of us just think of what we did last week and approximate time. I think you can see how it's halfway hogwash. (I used the pig term instead of the cow term. I'll be polite.) Halfway legit may just be good enough though. It depends on how meticulous your tracking is meant to be. Whatever. Your glass is half full.