Google had earlier confirmed that Android 11 will be rolled out in Q3 this year. It has now specified the date as well.
Android 11 Beta
You can try out the new Android 11 beta version even if you are not on the Pixel. And if and when you are done with it, you can also opt out.
Just a week after rolling out the first beta version, Google is back with a new build that fixes some bugs in the Android 11 Beta.