See, this kind of thing bugs me - why should you have to use up your holiday allowance if the company chooses to close for the day?
The same thing happened at my workplace. Every year, 3 of our holiday days had to be set aside for the Christmas break. However this year, they told us it had to be 4 days, as Christmas Eve is a Monday and management had chosen to close the site. This didn't please many people as it contradicted the inclement weather policy, which stated that if management chose to close the site because of bad weather, we would have a paid day off. We ended up settling on working a full day on Friday (we usually finish at 1pm), and having the Monday off as a paid day - as a compromise. It seems that some companies have us over a barrel when it comes to holiday pay.