CLST/CLT
Chile Summer Time
GMT -3
12am
3am
6am
9am
12pm
3pm
6pm
9pm
CLT is not used on this date
This converter uses CLST (GMT -3), the offset Santiago uses on this date. Open the CLST converter.
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.

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

Time Difference

Chile Summer Time is 1 hour ahead of Atlantic Standard Time
9:00 am09:00 in CLST is 8:00 am08:00 in AST

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

9:00 am09:00 Chile Summer Time (CLST). Offset UTC -3:00 hours
8:00 am08:00 Atlantic Standard Time (AST). Offset UTC -4:00 hours

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

CLSTAST
12am (midnight)11pm
1am12am (midnight)
2am1am
3am2am
4am3am
5am4am
6am5am
7am6am
8am7am
9am8am
10am9am
11am10am
12pm (noon)11am
1pm12pm (noon)
2pm1pm
3pm2pm
4pm3pm
5pm4pm
6pm5pm
7pm6pm
8pm7pm
9pm8pm
10pm9pm
11pm10pm
00:0023:00
01:0000:00
02:0001:00
03:0002:00
04:0003:00
05:0004:00
06:0005:00
07:0006:00
08:0007:00
09:0008:00
10:0009:00
11:0010:00
12:0011:00
13:0012:00
14:0013:00
15:0014:00
16:0015:00
17:0016:00
18:0017:00
19:0018:00
20:0019:00
21:0020:00
22:0021:00
23:0022:00

Chile Standard Time

Offset: CLT is 4 hours behind Greenwich Mean Time (GMT) and is used in South America

CLT Time Zone Geo Map
CLT timezone map

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

Daylight saving time clock moves forward for one hour from 12am to 1amEnd: Chile Standard Time (CLT) ended on Sunday, September 7, 2025 at 12:00 am local time and clocks were set one hour forward to Sunday, September 7, 2025, 1:00 am local daylight time instead. Standard time ends annually on the first Sunday of September.

Daylight saving time clock moves back for one hour from 12am to 11pmStart: Chile Standard Time (CLT) starts on Sunday, April 5, 2026 at 12:00 am local time and clocks are set one hour back to Saturday, April 4, 2026, 11:00 pm. Standard time starts annually on the first Sunday of April.

CLT representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • -04 - basic short
  • -0400 - basic
  • -04:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • -0400 - sign character (-) followed by a four digit time providing hours (04) and minutes (00) of the offset. Indicates an offset of four hours to the west of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Quebec - Military abbreviation for CLT
  • Q - short form of 'Quebec'
Time zones with the GMT -4 offset:
  • AST - Atlantic Standard Time
  • EDT - Eastern Daylight Time
  • AMT - Amazon Time
  • BOT - Bolivia Time
  • CDT - Cuba Daylight Time
  • CLT - Chile Standard Time
  • FKT - Falkland Island Time
  • GYT - Guyana Time
  • HLV - Hora Legal de Venezuela
  • PYT - Paraguay Time
  • Q - Quebec Time Zone
  • VET - Venezuelan Standard Time

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