The power of the word "no" can be a pretty impressive thing, and we shouldn't be afraid to use it, specifically at this time of year.
"I really need to take a break, so, no, I can't track that in advance for you this year."
Every year, local bosses encourage their talent to remember they can use this word - without shame - and in fact, they'll probably have their back for using it. Union contracts even have provisions covering this sorta stuff.
"No, I'm not going to kill myself and stress myself out just to go away for a few days, I'm sorry."
Most bosses who understand the power of the human equation will probably agree.
Maybe someday, perhaps in 2011, we'll all learn how to use this magical word without feeling some sort of guilt or whatever.