AST
Atlantic Standard Time
GMT -4
AMST
Amazon Summer Time
GMT -3

Time Difference

Atlantic Standard Time is 1 hours behind Amazon Summer Time
9:00 am09:00 in AST is 10:00 am10:00 in AMST

AST to AMST call time
Best time for a conference call or a meeting is between 8am-5pm in AST which corresponds to 9am-6pm in AMST

9:00 am09:00 Atlantic Standard Time (AST). Offset UTC -4:00 hours
10:00 am10:00 Amazon Summer Time (AMST). Offset UTC -3:00 hours

9:00 am09:00 AST / 10:00 am10:00 AMST

AST AMST
12am (midnight) 1am
1am 2am
2am 3am
3am 4am
4am 5am
5am 6am
6am 7am
7am 8am
8am 9am
9am 10am
10am 11am
11am 12pm (noon)
12pm (noon) 1pm
1pm 2pm
2pm 3pm
3pm 4pm
4pm 5pm
5pm 6pm
6pm 7pm
7pm 8pm
8pm 9pm
9pm 10pm
10pm 11pm
11pm 12am (midnight)
0:00 1:00
1:00 2:00
2:00 3:00
3:00 4:00
4:00 5:00
5:00 6:00
6:00 7:00
7:00 8:00
8:00 9:00
9:00 10:00
10:00 11:00
11:00 12:00
12:00 13:00
13:00 14:00
14:00 15:00
15:00 16:00
16:00 17:00
17:00 18:00
18:00 19:00
19:00 20:00
20:00 21:00
21:00 22:00
22:00 23:00
23:00 0:00

Atlantic Standard Time

Offset: AST is 4 hours behind Greenwich Mean Time (GMT) and is used in Caribbean

Countries: It is used in following countries: Antigua & Barbuda, Anguilla, Aruba, Barbados, St Barthelemy, Bermuda, Caribbean NL, Canada, Curaçao, Dominica, Dominican Republic, Grenada, Greenland, Guadeloupe, St Kitts & Nevis, St Lucia, St Martin (French), Martinique, Montserrat, Puerto Rico, St Maarten (Dutch), Trinidad & Tobago, St Vincent, Virgin Islands (UK), Virgin Islands (US)

Principal Cities: The largest city in the AST timezone is Santo Domingo from Dominican Republic with population about 2.202 million people. Other major cities in the area are Santiago de los Caballeros, Santo Domingo Oeste, San Juan, Halifax

Daylight Saving: Atlantic Standard Time (AST) is not adjusted for daylight saving therefore AST remains the same through out the year. This means, unlike some time zones where the clock is set forward by one hour every summer and backward by one hour during winter to adjust for daylight saving, Atlantic Standard Time remains the same

AST 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 four hour and zero minutes time differences to the west of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Quebec - Military abbreviation for AST
  • Q - short form of 'Quebec'
IANA/Olson: Reflects AST time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • America/Anguilla
  • America/Antigua
  • America/Aruba
  • America/Barbados
  • America/Blanc-Sablon
  • America/Curacao
  • America/Dominica
  • America/Glace_Bay
  • America/Goose_Bay
  • America/Grenada
  • America/Guadeloupe
  • America/Halifax
  • America/Kralendijk
  • America/Lower_Princes
  • America/Marigot
  • America/Martinique
  • America/Moncton
  • America/Montserrat
  • America/Port_of_Spain
  • America/Puerto_Rico
  • America/Santo_Domingo
  • America/St_Barthelemy
  • America/St_Kitts
  • America/St_Lucia
  • America/St_Thomas
  • America/St_Vincent
  • America/Thule
  • America/Tortola
  • America/Virgin
  • Atlantic/Bermuda
  • Canada/Atlantic
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
  • Arabian Standard Time - UTC +3
  • Acre Standard Time - UTC -5
  • Azores Standard Time - UTC -1
  • Apia Standard Time - UTC +13
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

Amazon Summer Time

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

AMST Time Zone Geo Map
AMST timezone map

AMST 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 three hour and zero minutes time differences to the west of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Papa - Military abbreviation for AMST
  • P - short form of 'Papa'
AMST Abbreviation: Several time zones share AMST abbreviation and it could refer to these time zones
  • Armenia Summer Time - UTC +5
  • Amazon Summer Time - UTC -3
Time zones with the GMT -3 offset:
  • ADT - Atlantic Daylight Time
  • PMT - Pierre & Miquelon Standard Time
  • PMST - Pierre & Miquelon Standard Time
  • WGT - West Greenland 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