Much like e-mail, calendaring has long established open protocols (like we DON’T have for social media) across services such as WebDAV, ics, etc. So it is usually quite easy to export/import a calendar elsewhere, or even to link to one or more remote calendars.
An app such as Thunderbird for example, can install on Windows, MacOS or Linux, and then connect to Google Calendar service online or many other external calendars. It’s just one way of extracting what you have in Google Calendar (or even GMail), and then either copying that to a local calendar, or to a calendar elsewhere that Thunderbird can also connect to.
If you want a cloud server version of e-mail (vs just on your desktop) you can host a NextCloud instance at home or online in a cheap VPS. The article also mentions the possibility of AgenDAV. If you have a Hubzilla social media account, you already have a calendar service in there too with WebDAV capability which you can use to sync through. Other online options are Zoho Apps or Trello too.
#technology #opensource #alternativeto #calendar