Countdown create by User

hi,
i try it but i cant find any reason ...

I would like to insert a function, that my user could insert in his profile a date in the future...  "Perhaps: 12-24-2006"

And in the signature shows how many time (Year-month-date-houres-seconds) is till the event arrived. Like a countdown....

Can u help me please?

Greetings
Michaela

P.S. I know, there is a lot of scripts for countdown, but i dont know how i include this in my PunBB for all my user.