See this message from ST:
New Incident Status: Monitoring
We have resolved the issue causing scheduled SmartApps to execute early, but many SmartApps may still be scheduled for the incorrect time. After running once, the schedule will be set for the correct time moving forward.
However, you can manually force the schedule to update to the correct time by going to the ‘Automation’ page in the SmartThings app, navigating to ‘SmartApps’, tapping on the SmartApp you need to re-schedule, and simply hitting ‘Done’ on the upper right. If it’s a Routine, you can do the same by going to the ‘Automation’ page and tapping the gear icon, then tapping ‘Done’ on the upper right.
Oct 14, 20:08 EDT