BCS Advent Calendar

[aberclive]

Has anyone been able to solve this familiar phrase?? The clues given are vague and I may have some of the letters wrong, but this is what I've got.

_ _ _ - _ _ E _ _ _ _ _ / _ _ _ / _ _ / _ _ _ _ _ _ _ _ O _

Letters to be used are :

P R T D S T W N G H B F G C R S B S T N
E A O I

I feel sure I must have some letter wrong as there doesn't seem to be enough vowels, but I've checked my answers and can't work out where I've gone wrong. Thanks for any help !!!

[goldnsilver]

Are any of the letters to be used more than once? What clues?

[aberclive]

The only clue given is that it is a familiar phrase....presumably a Christmas one or a Computer one as it is the British Computer Society Advent calendar.
None of the letters can be sued more than once , there are 24 spaces and 24 available letters. Mind you with only 4 vowels apart from the 2 given, I wonder if I may have some of the letters wrong...but I've checked my answers and I don't think I have.