There was 4 main days everyone at work wanted off over Christmas and I didn’t get the day I was asked for (despite being away with family) and the reason given was the work volumes are too high.
I’ve since found out that a colleague was allowed to leave 2 hours early on Christmas Eve - despite high work volumes 
They went out drinking after work so it was not an emergency. They can do what they want in their own time and my issue is not with them.
My issue is that if my request is ignored then management shouldn’t allow others to leave early?