Microsoft is going to end support for both of its currently running mobile OS, Windows Phone 7.8 and Windows Phone 8 in 2014. Folks over Plaffo has spotted a table which states that Microsoft will stop support for WP 8 on July 8 2014 and WP 7.8 on September 9 2014.
What Is Support Life Cycle?
Microsoft release updates and fixes time to time for its OS, once life cycle period ends then Microsoft stop releasing those updates and security fixes. At the time of release of OS, Microsoft define the date of life cycle end period.
Will my phone work after these dates?
Yes, of course, end of support doesnt means your phone will stop working, it will work fine but it wont get any further updates