ZydoSEO - 3:44 am on Dec 15, 2012 (gmt 0)
There are lot of thing bing doesn't know. For example the time and date it indexed some particular pages...
Just because they don't expose date/time indexed in the SERPs or the external tools that we have access to does not mean they don't "know" it.
Their index is filled with all kinds of date/time stamps for events that they use interally but don't expose through their search interface or external tools.
I'd be willing to bet a month's salary that they "know" the date/time each URL in their index was was last crawled, the date/time it the URL was first indexed, the date/time the URL was last indexed, and more.
They might not "show" it, but they definitely "know" it.