$CreationDate
$CreationDate gives the date and time at which the particular release of the Mathematica kernel you are running was created.
$CreationDate is in the form year, month, day, hour, minute, second returned by Date. See The Mathematica Book: Section 2.13.5. See also: $VersionNumber, $ReleaseNumber, FileDate, $InstallationDate.
$CreationDate gives the date and time at which the particular release of the Mathematica kernel you are running was created. 
year, month, day, hour, minute, second
returned by Date. 
