I am making a simple Christmas themed flash game as a viral marketing campaign for my site.

I wanted people opinions on the best time to release it.

I am offering a prize for the highest score, so there needs to be a cut off point, and therefore hopefully a surge of activity, but I am not sure when this should be.

I though maybe releasing this on 14th December, its mainly initially being sent to customers/clients and hopefully they will be winding down for xmas by then. But then there is the question of the cut off point. I was thinking the 23rd Dec, but would alot of people have stopped working for xmas by then? From the 14th this only gives 9 days of play, is this enough for a viral game to do its job properly?

Perhaps releasing on the 7th Dec, and running for 2 weeks would be better?

Any thoughts much appreciated