MST to EST Converter | Mountain to Eastern

MST to EST Conversion Table

Offset: MST +2 hours = EST. Applies during standard time. Work hours (9 AM–5 PM) highlighted.

MST		EST
00:00		02:00
01:00		03:00
02:00		04:00
03:00		05:00
04:00		06:00
05:00		07:00
06:00		08:00
07:00		09:00
08:00		10:00
09:00		11:00
10:00		12:00
11:00		13:00
12:00		14:00
13:00		15:00
14:00		16:00
15:00		17:00
16:00		18:00
17:00		19:00
18:00		20:00
19:00		21:00
20:00		22:00
21:00		23:00
22:00		00:00 (+1 day)
23:00		01:00 (+1 day)

Teams in Denver, Salt Lake City, and Phoenix regularly coordinate with East Coast offices in New York, Washington, and Atlanta. The Mountain–to–Eastern conversion is common in government contracting, aerospace (Colorado’s defence industry), and financial services.

Eastern Standard Time is UTC−5 and Mountain Standard Time is UTC−7, producing a 2-hour gap. When it’s 9 AM in Denver, it’s 11 AM in New York. Both zones observe US daylight saving time on the same schedule, so the 2-hour difference holds year-round.

Note: Arizona (Mountain time zone) does not observe DST. During summer, Arizona effectively aligns with Pacific Daylight Time. If your Mountain-time colleague is in Arizona, verify whether they are on MST or MDT.

Daylight Saving Time: What Changes

Both MST and EST observe daylight saving time. Since they typically switch on the same schedule, the 2-hour difference stays constant year-round — except during the brief transition windows when one zone has switched and the other hasn't yet. During those 1-2 weeks, the offset shifts by one hour.

Frequently Asked Questions

What is the time difference between MST and EST?

EST is 2 hours ahead of MST. When it is 10 AM in Denver, it is noon in New York. This 2-hour gap is constant year-round because both zones shift to daylight saving time on the same dates.

Does DST change the MST-to-EST offset?

No, as long as both locations observe DST. Both Mountain and Eastern shift on the same US schedule, keeping the gap at 2 hours. The exception is Arizona, which does not observe DST and stays on MST year-round.

What is the best meeting window for Mountain and Eastern?

The overlap is generous. Aim for 9 AM–4 PM Mountain (11 AM–6 PM Eastern). The 2-hour gap is small enough that most of the workday overlaps comfortably.

MST to EST Converter | Mountain to Eastern

MST to EST Conversion Table

Daylight Saving Time: What Changes

Frequently Asked Questions

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Your calendar + time zones, at a glance.

MST to EST Converter | Mountain to Eastern

MST to EST Conversion Table

Daylight Saving Time: What Changes

Frequently Asked Questions

Related Conversions

Learn More

Your calendar + time zones, at a glance.