Calculation of your local timezone offset is done by comparing your system clock against the UTC clock time which comes from the clock.xmission.com server. It is subject to error if your local clock is improperly set and can be also entirely wrong if your clock is fast and recently past the top of the hour. The offset calculation can usually be corrected by reloading this page. All times on this page are offset by the inherent loading time of the web. If you want accuracy, use NTP. Most modern systems have built-in NTP support and synchronizing to clock.xmission.com is open to the public.