If your file is hosted on FMS then using a server-side script schedule is the way to go. But you'll need to use the smtp email option, not the email client option.
Is your file hosted?
Without server, it's still possible to automate this. So follow Wim's advice if you can. If you can't:
There are system level task schedulers on both windows and Mac system. On the windows side, it's called Windows Scheduled Tasks. You can set up this utility to open a Filemaker file at a specified time. If you then set up a script in the file with the OnFirstWindowOpen trigger, opening this script can run a file in this file that then uses Perform Script to perform your script in your original file.
This is called a "robot file" and we often end up using this trick when we have a script to automate that cannot be run from a server context.
do you know the Mac equivalent to "Windows Scheduled Tasks", Phil?
I know they have one as others have mentioned this. The term "Chronos" floats up out of my organic database unit, but I'm not sure of the spelling nor if the latest versions of Mac use it. I also seem to recall the term "ical" also coming up.
Hmmm, perhaps this link?
cool! I've used the Windows Scheduled tasks, but never anything on MacOS.