After adding a new Goals feature on Android and iOS, Google Calendar will now send users event notifications on the web. Google is likely moving away from using email notifications as Drive recently added a similar capability.
Calendar has long had the ability to send out notifications on the web, but required users to enable the ‘Gentle Notifications’ lab in settings. Those who already use the lab will have the new feature automatically turned on. For everybody else, browser notifications are opt-in and can be enabled in the settings menu.
The feature will work in parallel with email notifications, though it appears that Google is moving towards sending users less alert messages to their inbox. This feature requires a browser that supports web notifications. In Google Chrome, users will see a notification with the Calendar icon, event title, and time. Clicking it will take users to the details page of that event.
Web notifications will be rolling out to users over the next two weeks. In the mean time, the old lab is still available and works exactly the same.