Riyadh to MDT
-9hRiyadh
ASTSOURCEMDT
MDTGreen rows indicate typical business hours (9 AM - 5 PM)
AST and MDT on the World Map
The map below highlights the AST (Arabia Standard Time) and MDT (Mountain Daylight Time) timezone regions across the globe.
AST – Arabia Standard Time
UTC+03:00Arabia Standard Time (AST, UTC+03:00) is the time zone for Saudi Arabia and the other Gulf states of the Arabian peninsula.
- •None of the Gulf states on Arabia Standard Time observe daylight saving.
- •AST is the same offset as Moscow Standard Time and East Africa Time.
- •Riyadh is one hour ahead of Central European Time in winter.
- •The AST abbreviation is shared with Atlantic Standard Time (UTC-04:00).
MDT – Mountain Daylight Time
UTC-06:00Mountain Daylight Time (MDT) is the daylight saving offset in the Mountain Time Zone, 6 hours behind UTC.
- •MDT shares the same offset as CST (UTC-06:00).
- •Arizona does not switch to MDT, remaining on MST.
About Riyadh
WikipediaRiyadh operates on Arabia Standard Time (AST), UTC+3. As OPEC's de facto capital and home to Tadawul, Riyadh time impacts global energy markets.
Riyadh is growing rapidly as part of Saudi Vision 2030 modernization.
Riyadh vs MDT: Offsets, DST and Best Call Times
Riyadh runs on Arabian Standard Time (AST) at UTC+03:00. MDT runs on Mountain Daylight Time (MDT) at UTC-06:00. That puts Riyadh 9 hours behind MDT — a difference of -9h at the current offsets.
In practice, when it is 9:00 AM in Riyadh it is 12:00 AM in MDT. Midnight in Riyadh is 3:00 PM in MDT. Neither zone observes daylight saving time, so the offset between them stays constant all year.
Riyadh to MDT time conversion table
| Riyadh (AST) | MDT (MDT) | Day |
|---|---|---|
| 12:00 AM | 3:00 PM | previous day |
| 6:00 AM | 9:00 PM | previous day |
| 7:00 AM | 10:00 PM | previous day |
| 8:00 AM | 11:00 PM | previous day |
| 9:00 AM | 12:00 AM | same day |
| 12:00 PM | 3:00 AM | same day |
| 3:00 PM | 6:00 AM | same day |
| 5:00 PM | 8:00 AM | same day |
| 6:00 PM | 9:00 AM | same day |
| 9:00 PM | 12:00 PM | same day |
Why people convert Riyadh to MDT time
- Scheduling a call from Riyadh to MDT: a 10:00 AM start in Riyadh lands at 1:00 AM in MDT, so you can confirm the slot without doing the arithmetic yourself.
- Handling a -9h gap: Riyadh and MDT have no overlap inside a normal 9-to-5 day, so real-time meetings need an early-morning or late-evening slot on one side. 9:00 AM in MDT is 12:00 AM in Riyadh.
- Keeping family and friends in sync: knowing that 8:00 PM in Riyadh is 11:00 AM in MDT makes it easy to avoid calling at 3 AM.
- Always state the zone abbreviation, not just the hour. "3:00 PM AST" is unambiguous; "3 PM" across a -9h gap is not.
- With a -9h gap there is no shared 9-to-5 window, so alternate the early start: one week Riyadh takes the early slot, the next week MDT does.
About AST (Arabia Standard Time)
Arabia Standard Time (AST) is fixed at UTC+03:00 all year across Saudi Arabia, Qatar, Kuwait, Bahrain, Iraq and Yemen. None of these countries observes daylight saving time, so the offset never changes. The abbreviation collides with Atlantic Standard Time (UTC-04:00) used in eastern Canada and the Caribbean; this page covers the Arabian peninsula meaning. Arabia Standard Time is the same offset as Moscow Standard Time and East Africa Time, which makes scheduling with Europe straightforward — Riyadh is one hour ahead of Central European Time in winter and level with it during European summer time.
About MDT (Mountain Daylight Time)
Mountain Daylight Time (MDT) is observed during summer months in the Mountain Time Zone, except in Arizona which stays on MST year-round. MDT aligns with Central Standard Time (CST) at UTC-06:00.
Best time to call between Riyadh and MDT
With a -9h offset there is no overlap inside a normal 9 AM – 5 PM day. MDT opens at 9:00 AM MDT, which is 12:00 AM in Riyadh, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
Riyadh and MDT have no shared working hours because of the -9h gap. Teams need to alternate early starts or rely on asynchronous handovers.
Riyadh is 9 hours behind MDT (AST UTC+03:00 → MDT UTC-06:00). There is no shared 9-to-5 window, so plan around an early or late slot. Remember to re-check around daylight-saving transitions.
🕐 Daylight Saving Time Info
Riyadh
Does not observe DST
MDT
☀ Currently in DST
Standard: UTC-07:00 · DST: UTC-06:00
Clocks fall back on Sun, Nov 1, 2026
Learn More About Time
Dive deeper into the fascinating world of timekeeping, time zones, and how they shape our global society:
Frequently Asked Questions
What is the time difference between Riyadh and MDT?
Riyadh (AST, UTC+03:00) is 9 hours behind MDT (MDT, UTC-06:00). The gap is currently -9h.
How do I convert Riyadh time to MDT time?
Add -9h to Riyadh local time. For example, 9:00 AM in Riyadh is 12:00 AM in MDT.
What time is it in MDT right now?
MDT uses MDT at UTC-06:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -9h offset from Riyadh.
What is the best time to call MDT from Riyadh?
There is no shared working-hours window because of the -9h gap. The closest option is 1:00 PM in Riyadh, which is 4:00 AM in MDT.
Which is behind, Riyadh or MDT?
Riyadh is 9 hours behind MDT. When it is 12:00 PM in Riyadh it is 3:00 AM in MDT.
Do Riyadh and MDT use different time zones?
Riyadh (Saudi Arabia) uses AST at UTC+03:00, while MDT uses MDT at UTC-06:00. The IANA identifiers are Asia/Riyadh and America/Denver.
Does daylight saving time affect the Riyadh–MDT difference?
Neither zone observes daylight saving time, so the -9h offset between Riyadh and MDT is fixed all year.
Which other cities share Riyadh's time zone?
AST also covers Riyadh, Jeddah, Doha, Kuwait City, Baghdad.
Which countries use AST, Riyadh's zone?
AST is used in Saudi Arabia, Qatar, Kuwait, Bahrain, Iraq, Yemen.
Is there a day difference between Riyadh and MDT?
Not normally. The -9h gap only pushes the date over the previous day.
What is the time difference between Riyadh and MDT?
MDT is -9h from Riyadh.
What timezone is Riyadh in?
Riyadh operates on Arabia Standard Time (AST), UTC+3. As OPEC's de facto capital and home to Tadawul, Riyadh time impacts global energy markets.
What timezone is MDT in?
MDT operates on its local timezone.
What are the business hours in Riyadh?
Standard business hours in Riyadh are 8:00 AM - 4:00 PM AST (Sunday-Thursday).
Which countries use AST (Arabia Standard Time)?
AST is used in Saudi Arabia, Qatar, Kuwait, Bahrain, Iraq, Yemen.
Does AST observe daylight saving time?
No, AST does not observe daylight saving time and remains at UTC+03:00 year-round.
What are some interesting facts about AST?
None of the Gulf states on Arabia Standard Time observe daylight saving. AST is the same offset as Moscow Standard Time and East Africa Time.
Which cities are in the MDT timezone?
Major cities in the MDT timezone include Denver, Calgary, Edmonton, Salt Lake City, Boise.
What is the UTC offset for MDT?
Mountain Daylight Time (MDT) is at UTC-06:00. During daylight saving time, it shifts to MST.
What should I know about the MDT timezone?
MDT shares the same offset as CST (UTC-06:00). Arizona does not switch to MDT, remaining on MST.
When is it midnight in Riyadh, what time is it in MDT?
When it is 12:00 AM (midnight) in Riyadh (AST), it is -9h later in MDT (MDT).
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