I'd think nothing of it... of taking a family vacation during school. Our school calendar is anything but friendly to working families. The school constantly closes 2 hours early because they can do so and still count it as a full school day for purposes of meeting standards. It gets on my nerves.. Why not close for a WHOLE day once instead of closing early several days.
If the school ever made an issue out of it... I would just homeschool for that week. For people who say this is harder on the teachers, I say hogwash.. I used to teach in a school near a military base where the students in my class were changing every day. Not a big deal.
Family time is just as important as school. Some parents have jobs that prevent them from being able to take vacation when schools are normally closed.