SM4 Pirate, a late night post, and I should clarify... the only time I wouldn't reinput times is when working arrivals, a runway configuration change occurs and there are no blank slots for the next 60 mins or so. Generally the flow sorts the mess out the way he/she wants it and we get on with it. I'm sure that if you've got aircraft in the hold/vectoring all over the sky and a runway change occurs, you don't go re entering all the data again.
Quite frankly I don't know anyone who looks at the + or - as that is what Maestro thinks the error is, and is probably wrong.
Cheers,
R-S.