[Mas*Mind]

You don't necessery need a cronjob. If you're forum gets visited at least one time a day you can do it in another way:

Make a hidden template with the a timestamp in it

If a user visits the forum this timestamp is requested and is checked if it's a timestamp before today..If that's the case mail all today's birthdays and update the timestamp, if not: Do nothing..

In this way only one user get's the extra query's (and script-load)

It's not 100% secure, because if a forum isn't visited a day then no-one get's emailed, but most forums are visited at least one time a day. It's a solution that can be built into vb without the need for a cronjob