[CentOS] Timeout for a script

How could I make a script time out after nn minutes, if it's not finished by
then?

The practical context: I have a dozen or so of backup scripts in a directory
"daily", and they are run by cron like this:
> 0 23 * * 1-6 run-parts /root/daily

Sometimes one of the scripts hang, in which case the rest of the scripts are
delayed more than can be allowed.

- Jussi

--
Jussi Hirvi * Green Spot

NOTICE: Due to the rising energy costs, as well as current market
conditions, the Light at the End of the Tunnel has been turned off. We
apologise for the inconvenience.