To maybe save you some headaches:
ScheduledEvents do not run on any sandbox.
Since Sandboxes tend to fall asleep, Mendix has simply decided to not start ScheduledEvents on them.
Check whether the Boolean “Enabled” is Yes.
Check whether the start date/time is “server” while you are running it in local and testing with your native timezone.
Thanks. Hope that helps!
If you want to do this locally, you need to enable it (There is a checkbox in the ScheduledEvent configuration).
If you want to do it on the cloud, the event needs to be activated. After doing a deployment you can turn it on or off (On the page where you also change constants).
Mendix stores information on every scheduled event that is executed, so if you want to see whether or not a scheduled event has been executed, create a page somewhere in your admin section, and put a datagrid with System.ScheduledEventInformation on it. (make sure your admin user has the System.Admin user role).