Firmware prior to 2.1.0 required an interval time greater than 0 to actually schedule the program. Also, the end time is for programs that repeat, this defines an absolute end time that the program cannot be scheduled to run after. If you don’t want the program to repeat, put a very high interval (23 hours).
Once the firmware is updated the program scheduling becomes a lot clearer.
Thanks for the understanding and hopefully Ray can help with the firmware update issue.