Hello Lisa,
Thank you for your question about the auction ending time. If you refresh the page, the countdown will reset. The countdown is dependent on the Javascript in your browser, which can fall behind or get ahead. It's just there "for show" and does not represent the exact ending time that we maintain in our database. Also, our clocks are synced to the same service that the originating site uses.
Please let us know if you have any other questions, or require other assistance. We are happy to help.
bidslammer