Dear VanB –
Santa was very disappointed to hear that you coincidentally were on vacation this year when your birthday rolled around. This seemed extremely unfair given that you are always so concerned about the staff being noticed and celebrating their birthdays accordingly.
So, Santa in his infinite generosity has decided to give you a birthday for Christmas! Your first gift, a few office decorations, are designed to mark the occasion properly. So, to celebrate the occasion, please leave your office decorated and your door open throughout the day. Please leave this posted on your door so people who stroll by will remember to wish you a happy birthday.