Linux How to run script at certain time?

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http://stackoverflow.com – I have a text file containing a specific date and time. I want to be able to run a script at the time specified in that file. How would you achieve that? Create another script that runs in background (sort of a deamon) and checks every second if the current time is matching the time in the file? Is there another way? The machine is a linux server , Debian wheezy. Thanks in advance (HowTos)