Z to AST Converter
Quick answers
Z is 4 hours ahead of AST. Z uses GMT +0, and AST uses GMT -4 for this comparison.
For example, 12:00 pm Z is 8:00 am AST. Use the converter above to adjust the date or time and create a shareable meeting link.
Best meeting overlap: 1pm-5pm Z, which is 9am-1pm AST.
Compare Z time with AST time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.
Time Difference
Zulu Time Zone is 4 hours ahead of Atlantic Standard Time
12:00 pm12:00 in Z is 8:00 am08:00 in AST
Z to AST call time
Best time for a conference call or a meeting is between 1pm-5pm in Z which corresponds to 9am-1pm in AST
12:00 pm12:00 Zulu Time Zone (Z). Offset UTC 0:00 hours
8:00 am08:00 Atlantic Standard Time (AST). Offset UTC -4:00 hours
12:00 pm12:00 Z / 8:00 am08:00 AST
| Z | AST |
|---|---|
| 12am (midnight) | 8pm |
| 1am | 9pm |
| 2am | 10pm |
| 3am | 11pm |
| 4am | 12am (midnight) |
| 5am | 1am |
| 6am | 2am |
| 7am | 3am |
| 8am | 4am |
| 9am | 5am |
| 10am | 6am |
| 11am | 7am |
| 12pm (noon) | 8am |
| 1pm | 9am |
| 2pm | 10am |
| 3pm | 11am |
| 4pm | 12pm (noon) |
| 5pm | 1pm |
| 6pm | 2pm |
| 7pm | 3pm |
| 8pm | 4pm |
| 9pm | 5pm |
| 10pm | 6pm |
| 11pm | 7pm |
| 00:00 | 20:00 |
| 01:00 | 21:00 |
| 02:00 | 22:00 |
| 03:00 | 23:00 |
| 04:00 | 00:00 |
| 05:00 | 01:00 |
| 06:00 | 02:00 |
| 07:00 | 03:00 |
| 08:00 | 04:00 |
| 09:00 | 05:00 |
| 10:00 | 06:00 |
| 11:00 | 07:00 |
| 12:00 | 08:00 |
| 13:00 | 09:00 |
| 14:00 | 10:00 |
| 15:00 | 11:00 |
| 16:00 | 12:00 |
| 17:00 | 13:00 |
| 18:00 | 14:00 |
| 19:00 | 15:00 |
| 20:00 | 16:00 |
| 21:00 | 17:00 |
| 22:00 | 18:00 |
| 23:00 | 19:00 |
Zulu Time Zone
Offset: Z is 0 hours ahead Greenwich Mean Time (GMT) and is used in Military
Coordinated Universal Time (UTC) is the world time standard that regulates clocks and time. It is successor to Greenwich Mean Time (GMT). For casual use, UTC is the same as GMT, but is used by the scientific community.
UTC is the time standard commonly used across the world since 1972. It is used in many technical fields, like aviation industry and meteorologists, also used to synchronize time across internet networks.
Z representations, usage and related time zones
- Z - is the zone designator for the zero UTC/GMT offset, also known as 'Zulu' time
- +00 - basic short
- +0000 - basic
- +00:00 - extended
- +0000 - sign character (+) followed by a four digit time providing hours (00) and minutes (00) of the offset. Indicates the zero UTC/GMT offset.
- Zulu - Military abbreviation for Z
- Z - short form of 'Zulu'
- EGST - Eastern Greenland Summer Time
- GMT - Greenwich Mean Time
- WET - Western European Time
- AZOST - Azores Summer Time
- UTC - Universal Time Coordinated
- WT - Western Sahara Standard Time
- Z - Zulu Time Zone
Atlantic Standard Time
Offset: AST is 4 hours behind Greenwich Mean Time (GMT) and is used in North America
Countries using this time zone: 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 time zone is Santo Domingo in Dominican Republic, with about 2.202 million people. Other major cities in this time zone include Santiago de los Caballeros, Santo Domingo Oeste, San Juan, Halifax.
French: HNA - Heure Normale de l'Atlantique
Spanish: AST - Tiempo Estándar del Atlántico

Daylight Saving: This is a standard time zone. During summer, some places set clocks forward one hour for daylight saving time and observe Atlantic Daylight Time (ADT).
Start: Atlantic Standard Time (AST) started 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. Standard time starts annually on the first Sunday of November.
End: Atlantic Standard Time (AST) ends 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 local daylight time instead. Standard time ends annually on the second Sunday of March.
AST representations, usage and related time zones
- -04 - basic short
- -0400 - basic
- -04:00 - extended
- -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.
- Quebec - Military abbreviation for AST
- Q - short form of 'Quebec'
- 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
- Atlantic Standard Time - UTC -4
- Arabia Standard Time - UTC +3
- 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
