It depends. How long have you been running?? whats the rest of your schedule like?? how long are your runs?? etc... Theres no set amount of time you should be running.

You shouldnt just start running every day. You need to build up slowly so you dont get knee problems. Plus there are many other ways to work on conditioning besides running.

If you feel burnt out, theres no shame in taking a rest day. Thats how your body recovers and recuperates.