Does it really matter which method I use to calculate critical path?  Rita and other sources seem to use Day 0 with EF = ES+D, while the PMP PrepCast I am listening to starts projects on Day 1 and uses the formula EF = ES + D -1 (and +1 going backwards)..

Day 0 methods are faster (IMO) to calculate forwards and backwards, while the Day 1 method makes more sense to me when trying to specifically tie activities to a schedule.

So does it really matter?  I'm leaning towards using Day zero but want to make sure I am not missing anything.