S to MST Converter
Mountain Time is on daylight saving time: MDT (UTC−6) until Sun, Nov 1.
Arizona stays on MST (UTC−7).
Start by searching for a time zone, city, or town.
Add one or more places to compare local times, adjust the date, and share the result.
Quick answers
Selected conversion
6:00 am06:00 S (UTC-6), Oct 28, 2026 = 6:00 am06:00 MDT (UTC-6), Oct 28, 2026
S and MDT have the same local time.
S and MST examples
These examples always use S (UTC-6) and MST (UTC-7). They stay the same when you change the date or time above. The selected conversion may differ when daylight saving time applies.
S is 1 hour ahead of MST.
Most of Arizona stays on MST (UTC-7) all year. Places such as Denver use MDT (UTC-6) during daylight saving time, one hour later. For daylight-time examples, use S to MDT.
How the time difference changes
For most of the year, S and MDT have the same time. From Nov 1, 2026 to Mar 14, 2027, S is 1 hour ahead of MST.
For most of the year, working hours of 9:00 am to 6:00 pm in S correspond to 9:00 am to 6:00 pm in MDT. At other times of the year, working hours of 9:00 am to 6:00 pm in S correspond to 8:00 am to 5:00 pm in MST.For most of the year, working hours of 09:00 to 18:00 in S correspond to 09:00 to 18:00 in MDT. At other times of the year, working hours of 09:00 to 18:00 in S correspond to 08:00 to 17:00 in MST.
Compare S time with MST time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.
Time Difference
Sierra Time Zone and Mountain Daylight Time have the same local time.
6:00 am06:00 in S is 6:00 am06:00 in MDT
S to MDT call time
Best time for a conference call or a meeting is between 9am-6pm09:00-18:00 in S which corresponds to 9am-6pm09:00-18:00 in MDT
6:00 am06:00 Sierra Time Zone (S). Offset UTC -6:00 hours
6:00 am06:00 Mountain Daylight Time (MDT). Offset UTC -6:00 hours
6:00 am06:00 S / 6:00 am06:00 MDT
Choose an hour to update the converter. Day labels such as “next day” or “+1” are relative to the selected date in the first column. Use Up and Down arrow keys, Home or End to move between hours, then Enter or Space to select.
| S | MDT |
|---|---|
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Sierra Time Zone
Offset: S is 6 hours behind Greenwich Mean Time (GMT).
Countries using this time zone: Belize, Canada, Chile, Costa Rica, Ecuador, El Salvador, Guatemala, Honduras, Mexico, Nicaragua, United States
Principal Cities: The largest city in the S time zone is Mexico City in Mexico, with about 12.294 million people. Other major cities in this time zone include Chicago, Houston, Puebla, Santiago de Querétaro.
Daylight Saving: Some places on Sierra Time Zone (S) keep the same time all year, while others use S for only part of the year and change their clocks for daylight saving time; see upcoming clock changes worldwide.
Today some of the lighter areas are on UTC−5 (Central Daylight Time).
S representations, usage and related time zones
- -06 - basic short
- -0600 - basic
- -06:00 - extended
- -0600 - sign character (-) followed by a four digit time providing hours (06) and minutes (00) of the offset. Indicates an offset of six hours to the west of the zero meridian.
- Sierra - Military abbreviation for S
- S - short form of 'Sierra'
- CST - Central Standard Time
- CT - Central Time
- MDT - Mountain Daylight Time
- EAST - Easter Island Standard Time
- GALT - Galapagos Time
- S - Sierra Time Zone
Mountain Standard Time
Offset: MST is 7 hours behind Greenwich Mean Time (GMT).
Countries using this time zone: Canada, Mexico, United States
Principal Cities: The largest city in the MST time zone is Phoenix in the United States, with about 1.65 million people. Other major cities in this time zone include Ciudad Juárez, Hermosillo, Culiacán, Denver.
French: HNR - Heure Normale des Rocheuses
Spanish: MT - Zona Pacífico
Today the lighter areas are on UTC−6 (MDT).
Daylight Saving: This is a standard time zone. During summer, some places set clocks forward one hour for daylight saving time and observe Mountain Daylight Time (MDT).
End: Mountain Standard Time (MST) ended on Sunday, March 8, 2026 at 2:00 am02:00 local time and clocks were set one hour forward to Sunday, March 8, 2026, 3:00 am03:00 local daylight time instead. Standard time ends annually on the second Sunday of March.
Start: Mountain Standard Time (MST) starts on Sunday, November 1, 2026 at 2:00 am02:00 local time and clocks are set one hour back to Sunday, November 1, 2026, 1:00 am01:00. Standard time starts annually on the first Sunday of November.
See USA daylight saving time and upcoming clock changes worldwide.
MST representations, usage and related time zones
- -07 - basic short
- -0700 - basic
- -07:00 - extended
- -0700 - sign character (-) followed by a four digit time providing hours (07) and minutes (00) of the offset. Indicates an offset of seven hours to the west of the zero meridian.
- Tango - Military abbreviation for MST
- T - short form of 'Tango'
- America/Boise
- America/Cambridge_Bay
- America/Ciudad_Juarez
- America/Creston
- America/Dawson
- America/Dawson_Creek
- America/Denver
- America/Edmonton
- America/Fort_Nelson
- America/Hermosillo
- America/Inuvik
- America/Mazatlan
- America/Phoenix
- America/Shiprock
- America/Whitehorse
- America/Yellowknife
- Canada/Mountain
- Canada/Yukon
- MST
- MST7MDT
- Mexico/BajaSur
- Navajo
- US/Arizona
- US/Mountain
- MST - Mountain Standard Time
- PDT - Pacific Daylight Time
- YST - Yukon Standard Time
- T - Tango Time Zone