They accidently allowed you to open up the first advent prize a few hours ago, now fixed.
It's probably running off CET time, like last years Calendar did.
Who the hell does an advent calendar where it's entirely possible you won't get anything?
Probably the kind of people that learned from last years mistake of making a Calendar that could be exploited. It wasn't their fault, but a small number of players will always ruin it for the rest of us.
I applaud Gameforge's efforts this year and I hope we'll see a good variety of items each day.