u need to have filemaker server
WIth FileMaker server, some scripts can be scheduled to be performed periodically at a specific time of day.
You can also use a Operating System Utility such as Windows Task Manager to open a FileMaker file at a specified date and time. This "robot file" can be designed with a setting in file options to perform a script each time it is opened. That script can perform a script in your hosted file. This robot file runs like any other client of your hosted database and thus can perform a number of tasks that a server schedule controlled script cannot do.
The third option is to build a script into your file that is set to run each time you open the file at the start of your day. The script would check the current date and time against a table where you have set up specific dates and times and would then either launch a script that has "come due" on the schedule or use install ontimer to set it to run later in the current session (to get it to run at a specific time of day.)
Thanks for the answers! They are very helpful.