If you are trying to keep the numbers down, I would stick with your original list plus Burns day. I don't think you want to have to educate your boss on every saint and celebration and historical event of every Celtic nation, because then he's going to lose interest in your cause. Dig too deep, and your boss will decide that you're just looking for excuses to wear the kilt, and deny you.

Frank, a private company has a right to present a public image. It has a right to enforce its dress code, and Reggie's allowed him has the opportunity to challenge it. I think the system is working here.