MST to EST Converter (Mountain Time to Eastern Time)

EST is 2 hours ahead of MST.

Mountain Time covers Denver, Salt Lake City, Albuquerque, Boise, Billings and Cheyenne. Eastern Time is two zones east of it, so New York, Philadelphia and Atlanta are always two hours ahead of Denver. Because both zones change clocks on the same dates, the gap holds all year for these cities.

Arizona is the important exception. Most of the state stays on Mountain Standard Time all year and does not move its clocks. The Navajo Nation, in the northeast of Arizona, does observe daylight saving time. The converter follows the Denver rules, so for Phoenix the gap is two hours in winter and three hours in summer.

How to use this tool

1. Pick a date and time in MST. The date matters when daylight saving time is in force.
2. Read the matching time in EST, with both UTC offsets.
3. Use "Use current time" for now, or the tables below for a quick look.

Formula

EST time = MST time − (MST UTC offset) + (EST UTC offset)

The converter looks up both UTC offsets for the actual instant in the saved IANA time zone rules, so daylight saving changes are included automatically.

Example

Worked with the saved rules:

9:00 AM MST on March 2, 2026 = 11:00 AM EST

6:30 PM MDT on August 3, 2026 = 8:30 PM EDT

Time difference through the year

The difference depends on the date when either place moves its clocks. These are the offsets on two reference days, from the saved IANA rules:

Clock changes in 2026

Between these dates the difference shifts by the size of the change.

MST to EST time table

Each hour in Mountain Time with the matching Eastern Time time.

EST to MST time table

Each hour in Eastern Time with the matching Mountain Time time.

Hours that work in both places

Hours (on the January reference day) that fall between 8:00 AM and 8:00 PM in both MST and EST:

Phoenix and Arizona

For a Phoenix reader the table needs an extra step. In winter Phoenix and Denver share the same time. After the second Sunday of March Denver moves forward and Phoenix does not, so Phoenix then sits one hour behind Denver and three hours behind New York.

Hawaii and most of Arizona are the two parts of the United States that skip daylight saving time, apart from some territories. When a message simply says "MST", it can mean a Colorado winter or a year-round Arizona clock; ask which place it refers to.

Calling the East Coast from the mountains

Because the East Coast workday starts at 9:00 a.m. Eastern, which is 7:00 a.m. in Denver, mountain-zone staff who serve eastern clients often start early. On the other side, an Eastern employee wanting an answer before lunch has to write by 10:00 a.m. Eastern to reach a Denver colleague at 8:00 a.m.

Ski resorts, national parks and mountain towns quote opening hours in local time. A chairlift that closes at 4:00 p.m. in Salt Lake City is closing at 6:00 p.m. on the clock of a visitor's home in Washington.