In the graph below you see the time zone difference between Mountain Standard Time and Eastern Daylight Time. Drag the bubble to adjust the time and to see the corresponding time in the other time zone.
Mountain Standard Time is the time zone of the US and Canadian states around the Rocky Mountains when observing daylight saving time in the summer, including cities like Edmonton, Calgary, Denver and Salt Lake City. Eastern Daylight Time is the time zone of the Canadian and US East Coast when observing daylight saving time in the summer, with places like Montreal, Ottawa, New York, Washington D.C. And Miami.
Usually it is preferable to schedule meetings in the morning for the person in MST and after lunch for the person in EDT.
Mountain Standard Time is observed in the Western part of central US and Canada, as well as the North West corner of Mexico. It is 7 hours behind UTC and turns into MDT in the summer. The name Mountain Time comes from it covering the Rocky Mountains in Western United States. In Mexico, this time zone is known as Zona Pacifico (Pacific Zone).
Mountain Time is observed in parts of Canada, the US and Mexico. The only province in Canada to be fully covered by MST is Alberta whereas other provinces like British Columbia and Northwest Territories are split between MST and PST.
In the US, Arizona, Colorado, Montana, Utah and Wyoming are all observing Mountain Time but there is also a bunch where part of the state observe MST and part another time zone, like CST or PST.
In Mexico, it is only the states in the north western corner of the country, including Baja California, Sinaloa and Chihuahua that observe MST.
The largest city observing MST is Phoenix, followed by Denver and El Paso/Juarez.
Aside from Arizona and the Mexican state of Sonora, all other locations do observe DST, turning MST into MDT – Mountain Daylight Time. Given this, and the fact that not entire states observe the same time zone, it is always recommended to use a good time zone converter to convert specific locations’ times.
This is the summer time of the Eastern US, Canada and parts of the Caribbean. It is in effect between March and October for most locations and is four hours behind UTC. It is important to note that even within certain states, e.g. Florida, Michigan, and Tennessee there are locations that do NOT observe EST/EDT but instead belong to other time zones. The same goes for the Canadian provinces Ontario and Quebec.
Most of the Eastern seaboard of the US observe Eastern Daylight Time, as well as most locations in Eastern Canada although there are a few exceptions. Locations such as New York, Washington, Quebec and Ontario are all on Eastern Standard Time. Also some Caribbean locations such as Jamaica, Haiti and Panama are in this time zone.
With the exception of Panama, Jamaica and a couple of locations in Canada and the US daylight saving time is observed. Unless you are sure that the location you have in mind is truly in EST/EDT it is always better to use the exact location name rather than the time zone abbreviation.