Google Calendar is relaunching offline support for desktop users. Users will now be able to see their Google Calendar from four weeks prior or any time in the future, by day, week, or month offline when accessed through a computer. But you won’t be able to create or edit events, e-mail guests, or access tasks and reminders while using the Google Calendar offline.

source https://gadgets.ndtv.com/apps/news/google-calendar-offline-on-computer-google-chrome-web-2355836#rss-gadgets-all