JST to AST Converter
Time Difference
Japan Standard Time is 12 hours ahead of Atlantic Daylight Time
5:30 pm17:30 in JST is 5:30 am05:30 in ADT
JST to AST call time
Best time for a conference call or a meeting is between 7:30pm-9:30pm in JST which corresponds to 6:30am-8:30am in AST
5:30 pm17:30 Japan Standard Time (JST). Offset UTC +9:00 hours
5:30 am05:30 Atlantic Daylight Time (ADT). Offset UTC -3:00 hours
5:30 pm17:30 JST / 5:30 am05:30 ADT
JST | ADT |
---|---|
12am (midnight) | 12pm (noon) |
1am | 1pm |
2am | 2pm |
3am | 3pm |
4am | 4pm |
5am | 5pm |
6am | 6pm |
7am | 7pm |
8am | 8pm |
9am | 9pm |
10am | 10pm |
11am | 11pm |
12pm (noon) | 12am (midnight) |
1pm | 1am |
2pm | 2am |
3pm | 3am |
4pm | 4am |
5pm | 5am |
6pm | 6am |
7pm | 7am |
8pm | 8am |
9pm | 9am |
10pm | 10am |
11pm | 11am |
0:00 | 12:00 |
1:00 | 13:00 |
2:00 | 14:00 |
3:00 | 15:00 |
4:00 | 16:00 |
5:00 | 17:00 |
6:00 | 18:00 |
7:00 | 19:00 |
8:00 | 20:00 |
9:00 | 21:00 |
10:00 | 22:00 |
11:00 | 23:00 |
12:00 | 0:00 |
13:00 | 1:00 |
14:00 | 2:00 |
15:00 | 3:00 |
16:00 | 4:00 |
17:00 | 5:00 |
18:00 | 6:00 |
19:00 | 7:00 |
20:00 | 8:00 |
21:00 | 9:00 |
22:00 | 10:00 |
23:00 | 11:00 |
Japan Standard Time
Offset: JST is 9 hours ahead Greenwich Mean Time (GMT) and is used in Asia
Countries: It is used in following countries: Japan
Principal Cities: The largest city in the JST timezone is Tokyo from Japan with population about 8.337 million people. Other major cities in the area are Yokohama, Osaka shi, Nagoya shi, Sapporo
Daylight Saving: Japan Standard Time (JST) is not adjusted for daylight saving therefore JST 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, Japan Standard Time remains the same

JST representations, usage and related time zones
- +09 - basic short
- +0900 - basic
- +09:00 - extended
- +0900 - sign character (+) followed by a four digit time providing hours (09) and minutes (00) of the offset. Indicates nine hour and zero minutes time differences to the east of the zero meridian.
- India - Military abbreviation for JST
- I - short form of 'India'
- Asia/Tokyo
- Japan
- AWDT - Australian Western Daylight Time
- CHOST - Choibalsan Summer Time
- I - India Time Zone
- IRKST - Irkutsk Summer Time
- JST - Japan Standard Time
- KST - Korea Standard Time
- PWT - Palau Time
- TLT - East Timor Time
- ULAST - Ulaanbaatar Summer Time
- WIT - Eastern Indonesian Time
- YAKT - Yakutsk Time
Atlantic Standard Time
Offset: AST is 4 hours behind Greenwich Mean Time (GMT) and is used in North America
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
French: HNA - Heure Normale de l'Atlantique
Spanish: AST - Tiempo Estándar del Atlántico

Daylight Saving: This is a standard time zone, however during summer some places switch clocks for one hour forward when daylight saving comes into effect and observe Atlantic Daylight Time (ADT).
End: Atlantic Standard Time (AST) has ended on Sunday, March 9, 2025 at 2:00 am local time and clocks were set one hour forward to Sunday, March 9, 2025, 3:00 am local daylight time instead. Standard time ends annually the on second Sunday of March.
Start: Atlantic Standard Time (AST) starts on Sunday, November 2, 2025 at 2:00 am local time and clocks are set one hour back to Sunday, November 2, 2025, 1:00 am. Standard time starts annually the on first Sunday of November.
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 four hour and zero minutes time differences 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
- Arabian Standard Time - UTC +3
- Argentina Standard Time - UTC -3
- Azores Standard Time - UTC -1
- Apia Standard Time - UTC +13
- 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