Zarlin

https://wooting.io/

No macro keys on the left, but the whole keyboard can be macro-ed. Also the hall effect switches are just about indestructible.

Maybe mermaid fits your use case?

https://mermaid.js.org/

I use OneCalendar, it works with a lot of email/calendar hosts, looks good, and is very responsive.

Alternatively, Thunderbird has a calendar feature built-in.

(Edit) failed to see which community this was, OneCalendar is sadly not open source.