Forced vacation

My office has decided to close down over the coming Passover (Pessah) holidays. So we all get an extended vacation, while they steal 3 days from our holiday allowance. Very nice of them. Well impressed. As I work part-time, I'm not sure exactly how many days they should be taking from me, but it definitely shouldn't be 3. I think. Anyone know the law regarding this? Now I get a vacation forced upon me, while mrs. anglosaxy will be going in to work...so it looks like I'll be playing a lot of PlayStation or waxing down my surfboard, if the weather picks up...