If you are a regular Google Webmaster Tools user then you must have notice about the latest changes from them that Google has now removed the date from the Home page crawl field from the site overview page.
The field was grouped in the “Home Page Crawl” section.
Earlier it was:
Someone asked JohnMu about this issue at Google Groups, where JohnMu responded that the date was “frequently incorrect and not really that useful.”
Forum discussion at Google Groups.