click on "my settings" on the bar just under that clock, it's all the way to the left of the bar. in the page that comes up click on "options" in the menu running down the left of the screen, and on the page that opens scroll down to date and time settings.
What time do you expect it to say? For instance mine right now says I was last here at 11pm last night - even though I was here a few minutes ago, before I rebooted the computer. It's not something I take much notice of, unless I've been away for a bit and can't remember when I was last here.
The Last Visited time shown is obviously not a clock, just a way of checking when you were last logged in. In the same way as electronic banking sites have this facility, so you can check if someone else has been using your account [:0]
