Mountain time on the Eastern clock
Eastern is two hours ahead of Mountain. A 7:00 AM Mountain start is 9:00 AM in New York, and a 3:00 PM call in Denver is 5:00 PM in Atlanta. Enter your time or press Use now to get the Eastern one.
A note on Arizona. Most of Arizona stays on MST all year and does not move its clocks. This page follows Mountain time as Denver keeps it, so it switches to MDT in summer. A Phoenix reader should be careful: 9:00 AM in Phoenix is 11:00 AM in New York in January, but 12:00 noon in July, because New York has moved forward and Phoenix has not.
For Mountain-based staff dealing with the East Coast, the Eastern afternoon is the problem. Their 3:00 PM is 5:00 PM there, and by their 4:00 PM the Eastern office is closing. The hour-by-hour table lays a 9:00 to 17:00 Mountain day against the Eastern clock, where it becomes 11:00 AM to 7:00 PM, so the East Coast morning is lost.
Evening times cross midnight sooner than you might expect. 10:30 PM Mountain is 12:30 AM the next day in the East. Both zones switch on the same dates, so the two-hour gap holds all year for Denver. The swap button reverses the direction.
Worked examples
Questions about this tool
How many hours ahead is Eastern from Mountain?
Two hours for Denver and the other places that move their clocks. Phoenix is two hours behind in winter and three in summer.
Why does the page say MDT in some months?
Mountain time moves to daylight time in spring. MST is the winter name, MDT the summer one, and the page shows the one in effect.
Is a 5:00 PM Mountain meeting reasonable for the East?
It is 7:00 PM there, so it is after normal working hours.
Related tools
Where this comes from: IANA time zone database and the rules behind it ยท US Department of Transportation, uniform time and daylight saving time