For everyone using Windows, if you double click the clock in the system tray (lower right corner), a window will pop up. Click the "Time Zone" tab and you'll see your current time zone. So in order to find out when the Dragon Festival starts in your time zone, take the number in parentheses and add it to 7:00.
Example: Mine says "(GMT -06:00) Central Time (US & Canada)". So I would take -06:00 + 07:00 and get 01:00. So it would start for me at 1:00 am.