I'm having the same problem with the Jetpack stats that the user here had. Basically I can't get any stats on my site. I have a self-hosted site. I have not used the old WordPress.com stats plug-in. I had the same date issue but resolved it following the suggestion in the forum. Then when I logged in again, the date issue returned.
As far as I can tell I have everything configured correctly.
What do I need to do to fix this?