The green real-time clock is designed to sync to your computers time clock. Beyond that function and when you login, the associated tooltip will display further useful timezone information.
1) The first line in the tooltip will show the timezone you have selected in your control panel settings. If you're currently in a daylight savings timezone, select that option in your control panel timezone settings and the tooltip will also display DST.
2) The second line of the tooltip displays the server date (according to your selected timezone and DST settings) that your page request was completed and sent to your computer. This will be matching your current computer date.
3) The third line is the server time your page request was completed and sent to your computer, according to the timezone and DST settings you have selected in your control panel timezone settings. As our page-load times are generally fast, this tooltip time will almost match your real-time clock's seconds when the page load is fully completed on your computer. That is a good thing I'm sure. Your computers clock will certainly need to be synced to an internet time server for all of these date and time settings to be accurately reflected.
I hope that clears things up for anyone who was interested. If you would like to know how to achieve this functionality on your website, let me know and I'll post more on this topic.
Please Note: We have re-coded all the timezone settings and the user control panel for further ease of use, adding new preset configurations to help you display the time and date within the forums how you would like them to display. Advanced users can customize these settings further using custom coded settings.