If you occasionally need access to your calendar when you’re not connected to the internet, then Google Calendar’s web interface is getting a bit more useful. When Google rolled out a new UI for the app in 2018, that meant removing the ability to access the data in your browser without an internet connection.
Now Google’s Workspace Updates blog notes the feature is coming back, however individual users will need to enable it — the instructions are available here. If you don’t see the option yet, check back later, it’s rolling out over the next 15 days or so, or it may have been disabled by your admin. The blog post only mentions access for Workspace accounts (formerly known as G Suite), but the support page doesn’t note any limitation, so we’ll see if it comes to individual free users too.