Updating current time…
ADT
12am
3am
6am
9am
12pm
3pm
6pm
9pm
CDT
UTC−5
2h behind
12am
3am
6am
9am
12pm
3pm
6pm
9pm

Quick answers

Selected conversion

9:00 am09:00 ADT (UTC-3), Oct 18, 2026 = 7:00 am07:00 CDT (UTC-5), Oct 18, 2026

ADT is 2 hours ahead of CDT.

ADT and CDT examples

These examples always use ADT (UTC-3) and CDT (UTC-5). They stay the same when you change the date or time above. The selected conversion may differ when daylight saving time applies.

ADT is 2 hours ahead of CDT.

How the time difference changes

For most of the year, ADT is 2 hours ahead of CDT. From Nov 1, 2026 to Mar 14, 2027, AST is 2 hours ahead of CST. Briefly around clock changes, ADT is 3 hours ahead of CST or AST is 1 hour ahead of CDT.

For most of the year, working hours of 9:00 am to 6:00 pm in ADT correspond to 7:00 am to 4:00 pm in CDT. At other times of the year, working hours of 9:00 am to 6:00 pm in AST correspond to 7:00 am to 4:00 pm in CST.For most of the year, working hours of 09:00 to 18:00 in ADT correspond to 07:00 to 16:00 in CDT. At other times of the year, working hours of 09:00 to 18:00 in AST correspond to 07:00 to 16:00 in CST.

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

Time Difference

Atlantic Daylight Time is 2 hours ahead of Central Daylight Time.
9:00 am09:00 in ADT is 7:00 am07:00 in CDT

ADT to CDT call time
Best time for a conference call or a meeting is between 11am-6pm11:00-18:00 in ADT which corresponds to 9am-4pm09:00-16:00 in CDT

9:00 am09:00 Atlantic Daylight Time (ADT). Offset UTC -3:00 hours
7:00 am07:00 Central Daylight Time (CDT). Offset UTC -5:00 hours

9:00 am09:00 ADT / 7:00 am07:00 CDT

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
ADTCDT
10:00pm previous day
11:00pm previous day
12:00am
1:00am
2:00am
3:00am
4:00am
5:00am
6:00am
7:00am
8:00am
9:00am
10:00am
11:00am
12:00pm
1:00pm
2:00pm
3:00pm
4:00pm
5:00pm
6:00pm
7:00pm
8:00pm
9:00pm
22:00 previous day
23:00 previous day
00:00
01:00
02:00
03:00
04:00
05:00
06:00
07:00
08:00
09:00
10:00
11:00
12:00
13:00
14:00
15:00
16:00
17:00
18:00
19:00
20:00
21:00

Atlantic Daylight Time

Offset: ADT is 3 hours behind Greenwich Mean Time (GMT).

Countries using this time zone: Bermuda, Canada, Greenland

Principal Cities: The largest city in the ADT time zone is Halifax in Canada, with about 471,559 people. Other major cities in this time zone include Sydney, Moncton, Saint John, Fredericton.

French: HAA - Heure Avancée de l'Atlantique

Map of the areas on Atlantic Daylight Time (ADT)
ADT part of the year

Today all shaded areas are on ADT.

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

123456789101112Start: Atlantic Daylight Time (ADT) started 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. Daylight saving starts annually on the second Sunday of March.

123456789101112End: Atlantic Daylight Time (ADT) ends 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 local standard time instead. Daylight saving ends annually on the first Sunday of November.

See Canada daylight saving time and upcoming clock changes worldwide.

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 - Brasilia Time
  • CLST - Chile Summer Time
  • FKST - Falkland Islands Summer Time
  • FKT - Falkland Islands Time
  • GFT - French Guiana Time
  • P - Papa Time Zone
  • PYST - Paraguay Summer Time
  • PYT - Paraguay Time
  • SRT - Suriname Time
  • UYT - Uruguay Time

Central Daylight Time

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

Countries using this time zone: Canada, Mexico, United States

Principal Cities: The largest city in the CDT time zone is Chicago in the United States, with about 2.664 million people. Other major cities in this time zone include Houston, San Antonio, Dallas, Fort Worth.

French: HAC - Heure Avancée du Centre

Spanish: CT - Zona Centro

Map of the areas on Central Daylight Time (CDT)
CDT part of the year

Today all shaded areas are on CDT.

Daylight Saving: Central Daylight Time (CDT) is a daylight saving/summer time zone. During winter, some places set clocks back one hour and observe Central Standard Time (CST).

123456789101112Start: Central Daylight Time (CDT) started 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. Daylight saving starts annually on the second Sunday of March.

123456789101112End: Central Daylight Time (CDT) ends 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 local standard time instead. Daylight saving ends annually on the first Sunday of November.

See USA daylight saving time and upcoming clock changes worldwide.

CDT 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 CDT
  • R - short form of 'Romeo'
IANA/Olson: Reflects CDT time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • America/Chicago
  • America/Indiana/Knox
  • America/Indiana/Tell_City
  • America/Knox_IN
  • America/Matamoros
  • America/Menominee
  • America/North_Dakota/Beulah
  • America/North_Dakota/Center
  • America/North_Dakota/New_Salem
  • America/Ojinaga
  • America/Rainy_River
  • America/Rankin_Inlet
  • America/Resolute
  • America/Winnipeg
  • CST6CDT
  • Canada/Central
  • US/Central
  • US/Indiana-Starke
CDT Abbreviation: Several time zones share CDT abbreviation and it could refer to these time zones
  • Central Daylight Time - UTC -5
  • Cuba Daylight Time - UTC -4
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