You can schedule a reboot with a timer but I do not think there is anyway to have this be part of a permanent config.
The bigger question is why? What purpose would rebooting the router daily serve?
Your can set up a TCL script as a cron job to reboot the router, but as has been commented already, what is the problem you are trying to overcome by rebooting?
I always forget about TCL. Thanks for the reminder Mick.