Take a look at FramaDate:
https://framadate.org/abc/en/
A couple of years ago I had to start scheduling meetings online. One or
two participants didn't like using Doodle for perceived security reasons.
I actually ended up running my own instance of Framadate, and still do.
But the public one is fine.
--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK:
http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor