While Zoom gives you the option to create a meeting with “no fixed time” when you select the option for a recurring meeting, I advise against this for several reasons:
Problems with polling
Zoom will just keep adding poll questions across the entire semester, which means all of the old questions will still show up with new ones during a Zoom meeting unless you delete them as you go. You’re limited to 25 poll questions per meeting, so you may run out of capacity before the end of the semester if you don’t delete your questions from previous meetings.
Limited access to reports
You’ll have to go to the Zoom portal to download attendance reports, and it’s a lot more work to find reports at miamioh.zoom.us than in Canvas. Basically, you won’t see a link for reports for meetings with no fixed time in Canvas because they never move over to the “Previous Meetings” tab, which is where the link to a meeting’s report is located.
No calendar connection
Your class sessions will no longer appear in your Canvas course’s calendar, and you and your students won’t be able to add them to Google Calendar either.
The main advantage to using the “no fixed time” setting is that you can have an unlimited number of sessions, but you’re limited to 50 sessions with a recurring meeting that has days/times set. However, very few classes in higher ed meet 50 or more times in a term, so the challenges to the “no fixed time” setting seem to outweigh the benefits.