Convert MST (Mountain Standard Time) to EEST (Eastern European Summer Time)

Best time to schedule a meeting

Standard 9–5 working hours do not overlap at all between MST and EEST. Someone has to take an early or late call — or use asynchronous communication instead.

MST to EEST conversion table

About MST

Mountain Standard Time (MST) is UTC−7. It is used in Denver and Salt Lake City in winter, and Phoenix all year.

Mountain Standard Time is UTC−7. Denver and Salt Lake City use it in winter and switch to MDT in summer; Arizona does not switch at all and stays on MST year-round, which means Phoenix agrees with Denver in winter and with Los Angeles in summer. The Navajo Nation, inside Arizona, does observe daylight saving, so the state contains both. Any scheduling system that maps "Arizona" to "Mountain Time" without the no-DST flag will be an hour out for eight months.

About EEST

Eastern European Summer Time (EEST) is UTC+3. It is used in Athens, Helsinki and Kyiv in summer.

Eastern European Summer Time is UTC+3, the summer clock for Greece, Finland, Romania, Bulgaria and the Baltics. In summer it coincides with Moscow Time, which does not move — so Helsinki and Moscow agree for half the year and differ by an hour for the other half, without Moscow having changed anything.

Does this gap change with the seasons?

This gap is seasonal. The abbreviations themselves are fixed offsets, but the region on MST switches to MDT (UTC−6) from March to November, and the region on EEST switches to EET (UTC+2) from late October to late March. So the 10-hour figure on this page is correct for the part of the year when both places are actually on these abbreviations, and changes by an hour outside it.

Because both sides shift, there are also short windows each spring and autumn when one has changed and the other has not — the two regions do not switch on the same date. A recurring meeting set during one of those windows is an hour out for a week or two, which is the most common way this catches people.

This is the reason scheduling systems store an IANA zone such as Region/City rather than an offset or an abbreviation: the zone knows its own rules and the offset does not.

Frequently asked questions