Boulder, CO, USA to AST Ast
Time Difference
MDT (Mountain Daylight Time) is 6 hours behind Azores Summer Time
9:00 am09:00 in Boulder, CO, USA is 3:00 pm15:00 in AST
Boulder to AST call time
Best time for a conference call or a meeting is between 8am-12pm in Boulder which corresponds to 2pm-6pm in AST
9:00 am09:00 MDT (Mountain Daylight Time) (Boulder, CO, USA). Offset UTC -6:00 hours
3:00 pm15:00 Azores Summer Time (AST). Offset UTC 0:00 hours
9:00 am09:00 Boulder, CO, USA / 3:00 pm15:00 AST
| Boulder, CO, USA | AST |
|---|---|
| 12am (midnight) | 6am |
| 1am | 7am |
| 2am | 8am |
| 3am | 9am |
| 4am | 10am |
| 5am | 11am |
| 6am | 12pm (noon) |
| 7am | 1pm |
| 8am | 2pm |
| 9am | 3pm |
| 10am | 4pm |
| 11am | 5pm |
| 12pm (noon) | 6pm |
| 1pm | 7pm |
| 2pm | 8pm |
| 3pm | 9pm |
| 4pm | 10pm |
| 5pm | 11pm |
| 6pm | 12am (midnight) |
| 7pm | 1am |
| 8pm | 2am |
| 9pm | 3am |
| 10pm | 4am |
| 11pm | 5am |
| 0:00 | 6:00 |
| 1:00 | 7:00 |
| 2:00 | 8:00 |
| 3:00 | 9:00 |
| 4:00 | 10:00 |
| 5:00 | 11:00 |
| 6:00 | 12:00 |
| 7:00 | 13:00 |
| 8:00 | 14:00 |
| 9:00 | 15:00 |
| 10:00 | 16:00 |
| 11:00 | 17:00 |
| 12:00 | 18:00 |
| 13:00 | 19:00 |
| 14:00 | 20:00 |
| 15:00 | 21:00 |
| 16:00 | 22:00 |
| 17:00 | 23:00 |
| 18:00 | 0:00 |
| 19:00 | 1:00 |
| 20:00 | 2:00 |
| 21:00 | 3:00 |
| 22:00 | 4:00 |
| 23:00 | 5:00 |
Boulder Information
Time Zone
Abbreviation / Name
MDT - Mountain Daylight Time
HAR - Heure Avancée des Rocheuses
HAR - Heure Avancée des Rocheuses
UTC / GMT Offset
-6:00 hours during Mountain Daylight Time, currently in use.
-6:00 hours during Heure Avancée des Rocheuses.
-6:00 hours during Heure Avancée des Rocheuses.
Daylight Saving Time Change
0:00 hours - DST is in use
Daylight Saving Time Starts
Sunday, March 9, 2025 at 2:00 am local time. DST starts annually the on second Sunday of March. Clocks are turned forward 0 hour to Sunday, March 9, 2025, 3:00 am local daylight time instead. Also called Spring Forward or Summer Time.
Daylight Saving Time Ends
Sunday, November 2, 2025 at 2:00 am local time. DST ends annually the on first Sunday of November. Clocks are turned backward 0 hour to Sunday, November 2, 2025, 1:00 am local standard time instead. Also called Fall Back or switch to Winter Time.
Boulder Facts
Country
USA
State
Colorado
Alternative Names
Bolder, Boulder, Bouldur, WBU, ba'uldara, bo de, boldara, bolde xr, boldeo, boruda, bwldr, bwldr klradw, Болдер, Боулдер, Боулдър, בולדר, بولدر, بولدر، کلرادو, بولڈر، کولوراڈو, बाउल्डर, बोल्डर, โบลเดอร์, ボルダー, 波德, 볼더
Population
107,349
Currency
Dollar (USD)
Geographic Coordinates
40° 00' N Latitude / 105° 16' W Longitude
International Dialing Code
+1
Azores Summer Time
Offset: AST is 0 hours ahead Greenwich Mean Time (GMT) and is used in Atlantic
AST representations, usage and related time zones
W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
- Z - is the zone designator for the zero UTC/GMT offset, also known as 'Zulu' time
- +00 - basic short
- +0000 - basic
- +00:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
- +0000 - sign character (+) followed by a four digit time providing hours (00) and minutes (00) of the offset. Indicates zero hour and zero minutes time differences of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
- Zulu - Military abbreviation for AST
- Z - short form of 'Zulu'
AST Abbreviation: Several time zones share AST abbreviation and it could refer to these time zones
- Atlantic Standard Time - UTC -4
- Arabia Standard Time - UTC +3
- Argentina Standard Time - UTC -3
- Armenia Standard Time - UTC +4
- Azores Summer Time - UTC +0
- Apia Standard Time - UTC +13
Time zones with the GMT +0 offset:
- EGST - Eastern Greenland Summer Time
- GMT - Greenwich Mean Time
- WET - Western European Time
- AZOST - Azores Summer Time
- UTC - Universal Time Coordinated
- WT - Western Sahara Standard Time
- Z - Zulu Time Zone