Tell me how to use the phrase "on such short notice"?

My son goes to preschool every Monday, but I went to school with him today, on Tuesday since a teacher had a PTA meeting. I thought my son could be with me during the meeting, but a staff said no since a room was small. The staff allowed him to go to school during the meeting. Can I say, "Thank you for taking care of him on such short notice today" to the stuff in this situation?

Thanks a lot for your help!