Morning confusion

Alarm clock sounds, early morning... Is it really time to wake up? Wait, it's Saturday, I can go back to sleep. Uh, no, it's not, it's only Tuesday!

Wow! I have to say that hasn't happened to me before. I had plenty of sleep last night but for some reason my internal clock seemed to have been set back three days (or forward four). Luckily that was a quickly passing confusion since it was time to get ready for the day and for work.