A little clarification, please

So there I was, wrapping up a Friday afternoon. As the senior member on staff that particular Friday, I dismissed the rest of the office 15 minutes early, but I still had a few things that needed to be completed before I could close out the week. Two minutes before I log off, I see an email come through:

Hi. I work at XX school and just wanted a little clarification, please. Since my schedule is Monday-Friday, does that mean I get Saturday and Sunday off?

<chirp chirp chirp>

It was a long week. It was Friday afternoon. My professional filter was slipping. I struggled against a passive-aggressive 'are you an idiot' email response...my eventual reply?

'Yes.'