When I signed into Facebook this morning I was greeted by a notice that on this day in 1883 the railroad industry in North America began using the four timezones that are still in use today. Upon reading that notice I immediately remembered a TED-Ed lesson on the topic. Where did timezones come from? What is “standard time?” The answers to those questions and more can be found in the short TED-Ed lesson How Did Trains Standardize Timezones in the United States? Watch the video below.