Author here, had a lot of fun building this as it's just ~100 lines of Rust code + some CSS/HTML.
If someone is looking for a fun thing to contribute to during Hacktoberfest, the code is on Github: https://github.com/mre/zerocal
Will mainly use it for myself to send out event links to friends.
It's just Rust, so it can be. Will add a `main.rs` and some instructions, but PRs are welcome if someone beats me to it. ;)
https://github.com/mre/zerocal/issues/9