Riyadh
Denver
Convert AST to MST
Arabia Standard Time to Mountain Standard Time — Denver is 9 hours behind Riyadh
Quick Facts
Time Difference
-9 hours
AST Full Name
Arabia Standard Time
MST Full Name
Mountain Standard Time
AST to MST Conversion Table
Related Conversions
About AST and MST Time Zones
AST (Arabia Standard Time) is UTC+3 and covers cities like Riyadh, Jeddah, Baghdad. MST (Mountain Standard Time) is UTC-7 and covers cities like Denver, Phoenix, Salt Lake City.
When it's 12:00 PM (noon) in Riyadh (AST), it's 3:00 AM in Denver (MST). The time difference between AST and MST is 9 hours — Denver is behind Riyadh.
The 10-hour difference makes real-time overlap challenging — early morning calls (7–9 AM AST) work best.
Daylight Saving Time
MST observes Daylight Saving Time and becomes MDT (Mountain Daylight Time) during summer months, shifting clocks forward by 1 hour to UTC-6.
During DST transitions, the time difference between AST and MST may shift by ±1 hour. Always verify the current offset above for the most accurate conversion.
Use our world clock tool to compare Riyadh and Denver with a visual timeline, or browse more timezone conversions.
Frequently Asked Questions
What is the time difference between AST and MST?
Denver (MST) is 9 hours behind Riyadh (AST). The offset is -9 hours.
Is MST ahead or behind AST?
MST is 9 hours behind AST. AST is UTC+3 and MST is UTC-6.
When it's 12:00 PM in Riyadh, what time is it in Denver?
When it's 12:00 PM (noon) in Riyadh (AST), it's 3:00 AM in Denver (MST).
When it's 5:00 PM in Riyadh, what time is it in Denver?
When it's 5:00 PM in Riyadh (AST), it's 8:00 AM in Denver (MST).
Does MST change for Daylight Saving Time?
Yes. MST (Mountain Standard Time, UTC-7) becomes MDT (Mountain Daylight Time, UTC-6) in summer, shifting clocks forward 1 hour.