If you sometimes need to access your calendar when you are not connected to the internet, the Google Calendar web interface becomes a little more useful. When Google rolled out a new user interface for the app in 2018, This significated to take off the ability to access your browser data without an Internet connection.
Now Google Workspace Updates Blog note that the feature is returning, but individual users will need to activate it – instructions are available here. If you don’t see the option yet, check back later, it will roll out over the next 15 days or so, or it may have been disabled by your admin. The blog post only mentions access to Workspace (formerly G Suite) accounts, but the support page doesn’t notice any limitations, so we’ll see if it’s also individual free users.