Dori: I've sometimes wondered if doing it for a day here and there might help. It does give me a nice 'fresh start' feeling but if it's a moot point, why bother? Although it doesn't seem wise to me to plan to do a water fast of less than 72 hours, Dr. Joel Fuhrman says that it's sometimes more practical for folks to do a two-day "weekend fast" rather than the full-blown deal. My most recent fast started on a Friday morning (I ate Thursday night) and ended Sunday night for just that reason: convenience.