Actually the is policy in place that addresses sick calls on holidays. But let me give you a little advice. As an airline family you make your holiday celebrations on the day they happen to work out. The actual date isn't important. Celebrate on the day he's home. There is almost no greater strain and pressure that you can put on your jr pilot husband than being a psycho about saving him home on holidays. And your insisting on it will make his life miserable. You've got to roll with the punches in this business. I've been on reserve now a long time. I haven't had a Christmas or a Halloween or a Mother's Day off for the better part of 6 years. Deal with it or be miserable, it's your choice. A probationary F/O calling in sick for his first Christmas on the line had better have a valid medical issue or he may well be looking for work come New Years Eve.