The 91st of February

An academic calendar published by UWSP had a typo.  The 19th day of this month was written mistakenly as "91".  I was all set to ridicule such an error even though I make tons of errors every time I type. But when I tried to make a link to the problem, it had been corrected.  I am not surprised that those sharpies fixed it.  At least I have a printed version of the calendar showing the 91st.