Convert any time between MST and GST, with a full 24-hour table and the hours when both sides are actually at work.

MST to GST Time Converter

GST is 10 hours ahead of MST. The US Mountain states are currently on MDT (UTC-6:00), and GST is UTC+4:00.

Worth knowing right now. The US Mountain states are currently on MDT, not MST, because daylight saving is in effect. The 10 hours above is the gap between those two regions today, which is almost certainly what you want. Taken strictly as written, MST to GST is 11 hours.
MST
Mountain Standard Time
09:05:51 AM
Sunday, October 11, 2026
UTC-6:00
+10:00
hours difference
⇆ Reverse
GST
Gulf Standard Time
07:05:51 PM
Sunday, October 11, 2026
UTC+4:00

Best Time to Call Between MST and GST

Standard 9-to-5 hours in these two zones never overlap, so someone has to take the call outside their working day. The most workable window is 7:00 AM to 12:00 PM MST, which is 5:00 PM to 10:00 PM GST.

both at work MST only GST only neither  —  hours along the strip are MST.

MST to GST: Full 24-Hour Conversion Table

Shaded rows are working hours; the darker shade marks the hours when both zones are at work.

MSTGSTWorking hours
12:00 AM 10:00 AM GST only
1:00 AM 11:00 AM GST only
2:00 AM 12:00 PM GST only
3:00 AM 1:00 PM GST only
4:00 AM 2:00 PM GST only
5:00 AM 3:00 PM GST only
6:00 AM 4:00 PM GST only
7:00 AM 5:00 PM —
8:00 AM 6:00 PM —
9:00 AM 7:00 PM MST only
10:00 AM 8:00 PM MST only
11:00 AM 9:00 PM MST only
12:00 PM 10:00 PM MST only
1:00 PM 11:00 PM MST only
2:00 PM 12:00 AM next day MST only
3:00 PM 1:00 AM next day MST only
4:00 PM 2:00 AM next day MST only
5:00 PM 3:00 AM next day —
6:00 PM 4:00 AM next day —
7:00 PM 5:00 AM next day —
8:00 PM 6:00 AM next day —
9:00 PM 7:00 AM next day —
10:00 PM 8:00 AM next day —
11:00 PM 9:00 AM next day GST only

What MST and GST Actually Are

MST — Mountain Standard Time

Denver, Salt Lake City, Calgary — and Phoenix year-round. Standing at UTC-7:00 as written, and the region does change its clocks, so its live offset moves by an hour twice a year. The next change is on Sunday, November 1, 2026, to MST. Arizona stays on MST all year, so Phoenix and Denver are an hour apart for eight months and identical for four.

Arizona has stayed on MST year-round since 1968 — the Navajo Nation within it does observe daylight saving, making the state a patchwork.

GST — Gulf Standard Time

Dubai, Abu Dhabi, Sharjah, Muscat. Standing at UTC+4:00 as written, and the region does not change its clocks, so that offset holds all year. GST also refers to South Georgia Time (UTC-2), which you are very unlikely to want.

The Gulf states have never observed daylight saving, so Dubai's offset has been unchanged for decades — unusual stability for a region that grew as fast as it did.

What This Means in Practice

The date changes mid-working-day

For 3 of the eight hours in a normal MST working day, the equivalent GST time falls on a different calendar date. Anything scheduled in that stretch needs the date checked as well as the time, or a Tuesday call quietly becomes a Wednesday one at the other end.

This gap is not fixed

MST changes its clocks and GST does not, so the difference between them moves by an hour twice a year. A recurring meeting set now will drift for one side from Sunday, November 1, 2026 unless someone resets it.

Nearly opposite sides of the clock

At 10 hours apart, one side's morning is the other side's night. Handing work over at the end of a shift usually beats trying to get both parties in the same call.

Frequently Asked Questions

What is the time difference between MST and GST?

GST is 10 hours ahead of MST. That is the live figure. Taken strictly as written, the gap between MST and GST is 11 hours — the two differ because at least one of these regions is currently on daylight saving.

What is 9:00 AM MST in GST?

9:00 AM MST is 7:00 PM GST.

What are the best hours to schedule a call between MST and GST?

Standard business hours in these two zones do not overlap at all, so one side has to work outside the 9-to-5. The most workable window is 7:00 AM to 12:00 PM MST, which is 5:00 PM to 10:00 PM GST.

Does the difference between MST and GST change during the year?

Yes. MST observes daylight saving and GST does not, so the gap shifts by an hour at least twice a year. The next clock change is on Sunday, November 1, 2026.

Does MST always mean Mountain Standard Time?

Arizona stays on MST all year, so Phoenix and Denver are an hour apart for eight months and identical for four.

Does GST always mean Gulf Standard Time?

GST also refers to South Georgia Time (UTC-2), which you are very unlikely to want.

Converting between two time zones regularly? Bookmark this page — the clocks update live and the table follows daylight saving automatically.