Not 100% sure if I understood correctly...
The JSCH object itself gets updated at period Turnaround (if you select reload at Period turnaround.... )
If you changed a Workflow that gets started from the schedule - the changes will get active as soon as the workflow gets started from the JSCH object.
So if the workflow was intended to start in the evening by your JSCH - the new Version (of course) was executed.
Basically: as soon as you hit "SAVE" in an object the changes are written to DB.
What was your intention how and when the new workflow version should run?
cheers, Wolfgang