3 Day week for the kids, 5 for the teachers

The kids have election day and Thursday off.  Every year on election day, the teachers have workshops.  This year, we have a morning with workshops and the afternoon with parent teacher conferences.  On Thursday, the teachers have another morning of workshops and another afternoon filled with parent teacher conferences.  I'm not a teacher so I don't have conferences.  However, my contract says that I have to work 4 days this week.  My principal wants me to come in for a half day on election day for the workshops.  I didn't plan on coming in on Thursday.  The workshops that day have nothing to do with me so I'm not going to them.  Now I have to come in.  I do get paid extra for coming in on Tuesday though.  That's good!  Unfortunately, as of now, I have nothing to do on Thursday.  Hopefully my boss will find me something to do!  Otherwise I will sit in my room and twiddle my thumbs for 8 hours!