Can anyone advise a calendar solution to display events?

Use case
To conveniently show our developer meetups and let folks easily add their chosen meetups to their personal calendars.

I can just embed a Google calendar widget, but some fellow devs use Apple calendar or outlook, etc.

I like eventable.com - it is exactly what I want, but their backend is very slow and times-out making it mostly unusable =(

I use Jekyll for the website.

Thanks!