There is no overlap between 09:00–18:00 working days in these two places.
How many hours is MST behind EAT?
As abbreviations, EAT is always 10 hours ahead of MST: MST is UTC−7 and EAT is UTC+3. To convert, add 10 hours.
When the MST to EAT time difference changes
For most of the year EAT is 9 hours ahead of MST. From 1 November to 31 December 2026, EAT is 10 hours ahead of MST instead, because the two places change their clocks on different dates. Meetings booked by the usual gap land an hour off in those weeks.
Dates
EAT vs MST
Length
1 November 2026 to 31 December 2026
10 hours ahead
61 days
1 January 2027 to 13 March 2027
10 hours ahead
72 days
14 March 2027 to 6 November 2027
9 hours ahead
238 days
7 November 2027 to 31 December 2027
10 hours ahead
55 days
Calling hours for MST and EAT
When EAT is 9 hours ahead of MST: no shared 09:00 to 17:00 hours; try 08:00 in MST (17:00 in EAT).
When EAT is 10 hours ahead of MST: no shared 09:00 to 17:00 hours; try 07:00 in MST (17:00 in EAT).
Frequently asked questions about MST and EAT time
How many hours ahead is EAT of MST?
EAT (UTC+3) is 10 hours ahead of MST (UTC−7).
Does the time difference between MST and EAT change?
Yes. It is usually 9 hours ahead, but changes when one side moves its clocks: 10 hours ahead from 1 November to 31 December 2026; 10 hours ahead from 1 January to 13 March 2027.