Not effectively, no. Your best bet is to use one of the options I mentioned above.
1) What happens if you reboot? If you set a timer in the script and reboot, you will have to restart the script every time to keep it runnig. If it's set up as s scheduled task, it will work automagically when the computer reboots.
2) It's just not a very clean way of doing it. You don't want the script constantly running in the background waiting for a timer to trip/reset. That's what cron and Task Scheduler are for.
~Charlie