Google Calendar Show All от Andrei LAZAROV

Take control of your calendar!

This lightweight extension adds three simple buttons to your Google Calendar interface:
- Show all
- Hide all
- Toggle all

No more clicking each calendar one by one. Whether you're managing a busy work schedule or simplifying your personal view, this tool saves you time and clicks.

Free and open-source:
https://github.com/andrei-lazarov/GoogleCalendar-ShowAll