Calculating timezones can be confusing when you’ve got to do it often and aren’t especially keen on keeping up with which city is on daylight savings or isn’t. And while an hour may not seem like a significant amount of time, missing a phone call or meeting can be more than inconvenient, if not downright embarrassing. The free travelmath is a simple website that quickly tells you the difference in hours between any two given cities.
The interface is hardly the cleanest, unlike World Time Engine [original post], but it’s straightforward. Additionally, you can select a number of other time difference calculators, like drive time, flight distance, and latitude/longitude (a feature many high school students may find handy). travelmath also has a helpful meeting time suggestions, letting you know when the best overlapping hour to make a business call might be.
To always stay up on what time it is in the cities you work with most, I highly recommend my longtime favorite and previously mentioned Firefox extension Foxclocks.