I stayed in my office. I slept a bit with my head on the desk.
I am working on the schedules of my project for the academic/fiscal year 2012 starting from April. The deadline has passed. In the morning, I received an e-mail telling me to finish them as soon as possible. So I kept working.
A bachelor student I am instructing carried out his rehearsal for the graduation presentation right after lunch. The presentation was not very bad, but it needed to be modified.
While I was working, the student came in to my office for the discussion. We talked a lot about how to understand his data. We talked till 11 PM.
Therefore, I will stay in the office again tonight.