What is the date mentioned in @@version SQL Server I wanted to know what the date that is result of select @@vesion in SQL server refers to.

Microsoft SQL Server 2012 - 11.0.5058.0 (X64)   May 14 2014 18:34:29   Copyright (c) Microsoft Corporation  Enterprise Edition: Core-based Licensing (64-bit) on Windows NT 6.2  (Build 9200: )
Its the SQL Server build date for the installed version. Refer to @@version on MSDN.