HappyZebra.com is a collection of Travel Calculation tools and information about time zones, current local time / date, area codes and sunrise sunset in major cities with their time difference and flight distance with other cities. It is particularly useful for travellers who need to know the time difference and air distance between cities to plan their trip. By using the time difference calculator page you can see the time differences between cities or time zones. You can also see the list of time zones with their UTC / GMT offset.
HappyZebra.com started in 2007 and gradually grew to include information about more and more cities. The website is optimized for mobiles and the pages are designed for ease of use and navigation.