@Quiddity mentioned he uses https://framadate.org/ as an alternative to Doodle. Unfortunately that open source software does not have support for multiple timezones.
https://framagit.org/framasoft/framadate/framadate/issues/158 is the task, self assigned a week ago by Thomas Citharel. He happens to live in the city next to @hashar so should try to reach out to him and see what is going on on that front :-]