I understand the reasoning that you can't reasonably add EVERY possible holiday to the calendar, but it occurs to me that they get off all of July and August, plus part of June and September. They don't *actually* have to be off until the Tuesday after Labor Day, they really can start school the Thursday before if necessary to fit these extra holidays in.
On your left you will see the musings, ramblings, and prevarications of me, your most Imperial Highness Herself, and Keeper of the Red Pencil of Doom. To the right... probably the edge of your computer monitor. *shrugs* What can you do?