I found that the secret to getting a particular day off, like Christmas etc. was to bid for an unpopular trip that got back to base the day before, which takes you completely out of the annual leave/requested days off scenario and puts back into the standard days off after a trip. When long haul, New York in winter not being particularly popular, I would bid for a ten day trip via Europe, from SE Asia, that got back on the 23rd December and then gave me the next three days off. Sometimes it is possible to use the system in your favour without getting mixed up with the stampeding herd!