Many people use Doodle Poll to find common availability.
https://doodle.com/free-poll
There is an Office 365 version of Doodle Poll but I’ve never seen anyone on campus use it. People probably don’t know it is available and I’ve never used it. I intend to try it out the next time I have this need.
https://findtime.microsoft.com/
If everyone had their Outlook calendar you could just use scheduling assistant.
https://support.microsoft.com/en-us/office/use-the-scheduling-assistant-and-room-finder-for-meetings-in-outlook-2e00ac07-cef1-47c8-9b99-77372434d3fa
To help make my student staff schedule, I had them submit availability in Qualtrics. https://bgsu.qualtrics.com
Here is a screen shot showing a Qualtrics question type called text entry that contains a form with 6 fields.
Question submitted by EDHD’s Project Impact.