I tried creating a routine requiring SmartThings to turn on a device for just a fixed amount of time, which I could find no way to accomplish. The "Control SmartThings" option only appears as an option once when creating a routine, allowing a device to be programmed to be turned on or off, but I could find no way to reverse this setting within the same routine. I was attempting to turn a device on for ten minutes under specific circumstances, and then turn this device off.
I think in your "time" setting select period. Start and end time and then the action it triggerred should reverse if it moves outside of that I believe.
I found a solution. I set it up to have SmartThings turn on the device followed by a 10 minute waiting period. After this I was able to use a typed Bixby Voice Quick Command to turn the device off!
