Only when a stable version is out and if you have clicked asked me what i want to do in TOOLS > OPTIONS > ADVANCE > UPDATE in session WHEN UPDATES TO FIREFOX ARE FOUND.

If you interesting about a calendar for future release:

https://wiki.mozilla.org/RapidRelease/Calendar

thank you

Please mark "Solved" the answer that really solve the problem, to help others with a similar problem.

Can we uninstall a browser update?

no, only downgrade to previous version

thank you

How?? Thanks

http://support.mozilla.com/en-US/kb/Installing%20a%20previous%20version%20of%20Firefox

thank you