Boulder to EST Time Converter

Updating current time…
Boulder
Colorado, USAMDT
UTC−6
12am
3am
6am
9am
12pm
3pm
6pm
9pm
EDT/EST
Eastern Daylight Time
UTC−4
12am
3am
6am
9am
12pm
3pm
6pm
9pm
Eastern Time is on daylight saving time: EDT (UTC−4) until Sun, Nov 1.
Use EST all year (UTC−5)

Quick answers

Selected conversion

6:00 am06:00 MDT (UTC-6), Oct 12, 2026 = 8:00 am08:00 EDT (UTC-4), Oct 12, 2026

Boulder is 2 hours behind EDT.

How the time difference changes

For most of the year, Boulder is 2 hours behind EDT. From Nov 1, 2026 to Mar 14, 2027, Boulder is 2 hours behind EST. Briefly around clock changes, Boulder is 1 hour behind EST or Boulder is 3 hours behind EDT.

For most of the year, working hours of 9:00 am to 5:00 pm in Boulder correspond to 11:00 am to 7:00 pm in EDT. At other times of the year, working hours of 9:00 am to 5:00 pm in Boulder correspond to 11:00 am to 7:00 pm in EST.For most of the year, working hours of 09:00 to 17:00 in Boulder correspond to 11:00 to 19:00 in EDT. At other times of the year, working hours of 09:00 to 17:00 in Boulder correspond to 11:00 to 19:00 in EST.

Compare Boulder time with EST time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.

Time Difference

MDT (Mountain Daylight Time) is 2 hours behind Eastern Daylight Time.
6:00 am06:00 in Boulder, CO, USA is 8:00 am08:00 in EDT

Boulder to EDT call time
Best time for a conference call or a meeting is between 9am-3pm09:00-15:00 in Boulder which corresponds to 11am-5pm11:00-17:00 in EDT

6:00 am06:00 MDT (Mountain Daylight Time) (Boulder, CO, USA). Offset UTC -6:00 hours
8:00 am08:00 Eastern Daylight Time (EDT). Offset UTC -4:00 hours

6:00 am06:00 Boulder, CO, USA / 8:00 am08:00 EDT

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.

Hourly time comparison
Boulder, CO, USAEDT
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Boulder Time Zone and Facts

Time Zone

Abbreviation / Offset
MDT – Mountain Daylight Time, UTC-6 (now, daylight saving time)
MST – Mountain Standard Time, UTC-7 (standard time)
Daylight Saving Time Ends
123456789101112Sunday, November 1, 2026 at 2:00 amSunday, November 1, 2026 at 02:00: clocks go back 1 hour to 1:00 am01:00 (MST). DST ends on the 1st Sunday of November each year. Also called Fall Back or Winter Time.
Daylight Saving Time Starts
123456789101112Sunday, March 14, 2027 at 2:00 amSunday, March 14, 2027 at 02:00: clocks go forward 1 hour to 3:00 am03:00 (MDT). DST starts on the 2nd Sunday of March each year. Also called Spring Forward or Summer Time.
Clock Changes
USA daylight saving time · Clock changes worldwide

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
106,803
Currency
Dollar (USD)
Geographic Coordinates
40° 00' N Latitude / 105° 16' W Longitude
International Dialing Code
+1
More About Boulder
Boulder local time and city facts

Eastern Standard Time

Offset: EST is 5 hours behind Greenwich Mean Time (GMT).

Countries using this time zone: Bahamas, Canada, Haiti, Jamaica, Cayman Islands, Mexico, Panama, Turks & Caicos Is, United States

Principal Cities: The largest city in the EST time zone is New York City in the United States, with about 8.804 million people. Other major cities in this time zone include Toronto, Montréal, Philadelphia, Port-au-Prince.

French: HNE - Heure Normale de l'Est

Spanish: ET - Tiempo del Este, ET - Zona Sureste

Map of the areas on Eastern Standard Time (EST)
EST all year EST part of the year

Today the lighter areas are on UTC−4 (EDT).

Open the world time zone map© OpenStreetMap

Daylight Saving: This is a standard time zone. During summer, some places set clocks forward one hour for daylight saving time and observe Eastern Daylight Time (EDT).

123456789101112End: Eastern Standard Time (EST) 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.

123456789101112Start: Eastern Standard Time (EST) 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 upcoming clock changes worldwide.

EST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • -05 - basic short
  • -0500 - basic
  • -05:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • -0500 - sign character (-) followed by a four digit time providing hours (05) and minutes (00) of the offset. Indicates an offset of five hours to the west of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Romeo - Military abbreviation for EST
  • R - short form of 'Romeo'
IANA/Olson: Reflects EST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • America/Atikokan
  • America/Cancun
  • America/Cayman
  • America/Coral_Harbour
  • America/Detroit
  • America/Fort_Wayne
  • America/Grand_Turk
  • America/Indiana/Indianapolis
  • America/Indiana/Marengo
  • America/Indiana/Petersburg
  • America/Indiana/Vevay
  • America/Indiana/Vincennes
  • America/Indiana/Winamac
  • America/Indianapolis
  • America/Iqaluit
  • America/Jamaica
  • America/Kentucky/Louisville
  • America/Kentucky/Monticello
  • America/Louisville
  • America/Montreal
  • America/Nassau
  • America/New_York
  • America/Nipigon
  • America/Panama
  • America/Pangnirtung
  • America/Port-au-Prince
  • America/Thunder_Bay
  • America/Toronto
  • Canada/Eastern
  • EST
  • EST5EDT
  • Jamaica
  • US/East-Indiana
  • US/Eastern
  • US/Michigan
Time zones with the GMT -5 offset:
  • CDT - Central Daylight Time
  • EST - Eastern Standard Time
  • ET - Eastern Time
  • COT - Colombia Time
  • CST - Cuba Standard Time
  • EASST - Easter Island Summer Time
  • ECT - Ecuador Time
  • PET - Peru Time
  • R - Romeo Time Zone
EST to ISTGMT to ESTPST to ESTEST to GMTPST to GMT