New Google Calendar coming soon.

https://support.google.com/calendar/answer/37082?hl=en

Share your calendar with someone
You can share your calendar with family and friends.

How sharing works
Here are a couple examples of what you can do with calendar sharing:

Share your main calendar with someone so they can see your schedule.

Create a new calendar that multiple people can edit, like a “Family” calendar that everyone in your family can add events to.
When you add someone to your calendar, you can decide how they see your events and whether they can also make changes like adding or editing events.

Share or unshare your calendar
In Google Calendar, you can have multiple calendars that you add events to. Each calendar can have different sharing settings.