you can easily workout a muscle or muscle group once every 7-10 days and keep gaining. of course the gains will be slower than if you worked out the same every 4-5 days.
many people once they get into a routine will do the same body part twice every 7-8 days, so it probably takes 3 good days to heal up. note: of course i have learned thru trial and error, when starting out or after a long break, it takes a helluva lot longer to heal!
pass - i try to make it there a couple nights a week around 6-7ish, also try to make it a couple mornings every week… those are rare occasions though.