I don't see much use in providing an empty "year" field, because if the user clicks on any of the arrows it will go to something as useful as year "-1" or "1".
E.g.: http://www.mediawiki.org/wiki/MediaWiki?action=history
Version: 1.21.x
Severity: minor
See Also:
https://bugzilla.wikimedia.org/show_bug.cgi?id=45580