Open source webapp to collaboratively decide a date/time across multiple timezones (alternative to Doodle)

Question

I have to schedule a hackathon with Open Source developers. We want to use only Open Source solutions.

Constraints:

• we don't want to host the application by ourselves → it has to be an existing website
• we don't want to force/to be forced to give our email addresses → it has to be usable without inscription
• we can make mistakes → polls and answers has to be editable
• if possible, we are looking for something also usable to do little polls (not only date polls)

Is there an Open Source alternative to Doodle?

Answer 1

Dudle fulfills all the requested points and has proven useful in its first usage.

Demo: https://dudle.inf.tu-dresden.de/?lang=en

License: AGPL Version 3

Source code: https://github.com/kellerben/dudle/

Answer 2

Rallly is a free collaborative scheduling service.
Limitation: It only allows voting on a date, not on a time.
Runnable with docker-compose.

Source code: https://github.com/lukevella/Rallly

Demo: https://rallly.co

MIT License

Answer 3

Framadate: Online service for planning an appointment or make a decision quickly and easily: Make a poll, Define dates or subjects to choose, Send the poll link to your friends or colleagues, Discuss and make a decision.
Written in PHP.

Source code: https://framagit.org/framasoft/framadate

Demo: https://framadate.org/

License: CeCILL-B (compatible with GPL)

Answer 4

Croodle seems to have the option to vote not only on dates but also on times.
Written in PHP.
Warning: I have not tested it, and there is no demo server.

Source code: https://github.com/jelhan/croodle

License: MIT