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ADT to BRT Converter

Updating current time…
AST/ADT
Atlantic Standard Time
GMT -4
12am
3am
6am
9am
12pm
3pm
6pm
9pm
ADT is not used on this date
This converter uses AST (GMT -4), the offset Moncton uses on this date. Open the AST converter.
BRT
Brasília time
GMT -3
12am
3am
6am
9am
12pm
3pm
6pm
9pm

Quick answers

For most of the year, ADT and BRT have the same time. During seasonal clock changes, AST is 1 hour behind BRT.

For most of the year, working hours of 9:00 am to 5:00 pm in ADT correspond to 9:00 am to 5:00 pm in BRT. During seasonal clock changes, working hours of 9:00 am to 5:00 pm in AST correspond to 10:00 am to 6:00 pm in BRT.

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

Time Difference

Atlantic Standard Time is 1 hour behind Brasília time
8:00 am08:00 in AST is 9:00 am09:00 in BRT

AST to BRT call time
Best time for a conference call or a meeting is between 9am-4pm in AST which corresponds to 10am-5pm in BRT

8:00 am08:00 Atlantic Standard Time (AST). Offset UTC -4:00 hours
9:00 am09:00 Brasília time (BRT). Offset UTC -3:00 hours

8:00 am08:00 AST / 9:00 am09:00 BRT

ASTBRT
12am (midnight)1am
1am2am
2am3am
3am4am
4am5am
5am6am
6am7am
7am8am
8am9am
9am10am
10am11am
11am12pm (noon)
12pm (noon)1pm
1pm2pm
2pm3pm
3pm4pm
4pm5pm
5pm6pm
6pm7pm
7pm8pm
8pm9pm
9pm10pm
10pm11pm
11pm12am (midnight)
00:0001:00
01:0002:00
02:0003:00
03:0004:00
04:0005:00
05:0006:00
06:0007:00
07:0008:00
08:0009:00
09:0010:00
10:0011:00
11:0012:00
12:0013:00
13:0014:00
14:0015:00
15:0016:00
16:0017:00
17:0018:00
18:0019:00
19:0020:00
20:0021:00
21:0022:00
22:0023:00
23:0000:00

Atlantic Daylight Time

Offset: ADT is 3 hours behind Greenwich Mean Time (GMT) and is used in North America

Countries using this time zone: Bermuda, Canada, Greenland

Principal Cities: The largest city in the ADT time zone is Halifax in Canada, with about 359,111 people. Other major cities in this time zone include Sydney, Dartmouth, Saint John, Moncton.

French: HAA - Heure Avancée de l'Atlantique

ADT Time Zone Geo Map
ADT timezone map

Daylight Saving: Atlantic Daylight Time (ADT) is a daylight saving/summer time zone, but some places set clocks back one hour during winter and observe Atlantic Standard Time (AST).

Daylight saving time clock moves forward for one hour from 2am to 3amEnd: Atlantic Daylight Time (ADT) ended on Sunday, November 2, 2025 at 2:00 am local time and clocks were set one hour back to Sunday, November 2, 2025, 1:00 am local standard time instead. Daylight saving ends annually on the first Sunday of November

Daylight saving time clock moves back for one hour from 2am to 1amStart: Atlantic Daylight Time (ADT) starts on Sunday, March 8, 2026 at 2:00 am local time and clocks are set one hour forward to Sunday, March 8, 2026, 3:00 am. Daylight saving starts annually on the second Sunday of March

ADT representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • -03 - basic short
  • -0300 - basic
  • -03:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • -0300 - sign character (-) followed by a four digit time providing hours (03) and minutes (00) of the offset. Indicates an offset of three hours to the west of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Papa - Military abbreviation for ADT
  • P - short form of 'Papa'
IANA/Olson: Reflects ADT time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • America/Glace_Bay
  • America/Goose_Bay
  • America/Halifax
  • America/Moncton
  • America/Thule
  • Atlantic/Bermuda
  • Canada/Atlantic
Time zones with the GMT -3 offset:
  • ADT - Atlantic Daylight Time
  • PMT - Pierre & Miquelon Standard Time
  • PMST - Pierre & Miquelon Standard Time
  • AMST - Amazon Summer Time
  • ART - Argentina Time
  • BRT - Brasília time
  • CLST - Chile Summer Time
  • FKST - Falkland Islands Summer Time
  • GFT - French Guiana Time
  • P - Papa Time Zone
  • PYST - Paraguay Summer Time
  • SRT - Suriname Time
  • UYT - Uruguay Time

Brasília time

Offset: BRT is 3 hours behind Greenwich Mean Time (GMT) and is used in South America

Countries using this time zone: Brazil

Principal Cities: The largest city in the BRT time zone is Fortaleza in Brazil, with about 2.4 million people. Other major cities in this time zone include Sao Luis, Natal, Teresina, Joao Pessoa.

Daylight Saving: Clocks in Brasília time (BRT) do not change for daylight saving time, so BRT stays the same throughout the year. Other time zones may set clocks forward in summer and back in winter.

BRT Time Zone Geo Map
BRT timezone map

BRT representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • -03 - basic short
  • -0300 - basic
  • -03:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • -0300 - sign character (-) followed by a four digit time providing hours (03) and minutes (00) of the offset. Indicates an offset of three hours to the west of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Papa - Military abbreviation for BRT
  • P - short form of 'Papa'
Time zones with the GMT -3 offset:
  • ADT - Atlantic Daylight Time
  • PMT - Pierre & Miquelon Standard Time
  • PMST - Pierre & Miquelon Standard Time
  • AMST - Amazon Summer Time
  • ART - Argentina Time
  • BRT - Brasília time
  • CLST - Chile Summer Time
  • FKST - Falkland Islands Summer Time
  • GFT - French Guiana Time
  • P - Papa Time Zone
  • PYST - Paraguay Summer Time
  • SRT - Suriname Time
  • UYT - Uruguay Time
EST to ISTGMT to ESTPST to ESTEST to GMTPST to GMT