This is what happens when you're gone.
In February, I took my student council students to our district meeting, and I left my students with a sub. Usually, I write the date as a math problem and update the daily celebration. But, I was busy and stressed and never got around to doing it that day.
I returned to school to find a math problem that correctly equaled the date and a newly invented holiday - Spongebob Squarepants Day.
I guess students do pay attention to the date and holiday on the board!