Sounds fun and interesting! The only problem I can see with it is that it would probably need a reboot at start and end of those days.
Expanding on your idea a little bit, maybe there could be some special event themed quests that earn you locked-to-char potions, that have the effect of removing all spell cooldowns for 1 hour, and there's enough quests that everyone can get maybe 3 or 4 of them each, and expire at end of event so must be used soon, that could spice things up especially if everyone uses them during a war or boss pk or something