In going for the all-important "Enthusiast" and "Fanatic" badges on SF, I've been pretty (er, um) enthusiastic about checking in daily.  Tonight I checked my SF account to see that I'm back to only one day of consecutive visits.  Tonight is Saturday, and I noticed this at 9pm Eastern Time.  Yesterday was Friday, and I know that I used SF while I was at work.

Where is this 'loss' coming from?  Are you using GMT to calculate the days?