JST to AST Converter
Trying to line up JST and AST? AST is 13 hours behind JST. Set any JST time below to see the matching AST time and date.
Daylight saving notes
In the United States and Canada, daylight saving time runs from the second Sunday in March to the first Sunday in November. That affects Atlantic Standard Time (AST).
JST to AST conversion chart
For example, a 9:00 AM JST meeting takes place at 8:00 PM AST (−1 day). Concretely, when Tokyo (JST) and Halifax (AST) set up a call, aST is 13 hours behind JST.
| JST time | AST time |
|---|---|
| 12:00 AM | 11:00 AM−1 day |
| 1:00 AM | 12:00 PM−1 day |
| 2:00 AM | 1:00 PM−1 day |
| 3:00 AM | 2:00 PM−1 day |
| 4:00 AM | 3:00 PM−1 day |
| 5:00 AM | 4:00 PM−1 day |
| 6:00 AM | 5:00 PM−1 day |
| 7:00 AM | 6:00 PM−1 day |
| 8:00 AM | 7:00 PM−1 day |
| 9:00 AM | 8:00 PM−1 day |
| 10:00 AM | 9:00 PM−1 day |
| 11:00 AM | 10:00 PM−1 day |
| 12:00 PM | 11:00 PM−1 day |
| 1:00 PM | 12:00 AM |
| 2:00 PM | 1:00 AM |
| 3:00 PM | 2:00 AM |
| 4:00 PM | 3:00 AM |
| 5:00 PM | 4:00 AM |
| 6:00 PM | 5:00 AM |
| 7:00 PM | 6:00 AM |
| 8:00 PM | 7:00 AM |
| 9:00 PM | 8:00 AM |
| 10:00 PM | 9:00 AM |
| 11:00 PM | 10:00 AM |
This chart uses the fixed JST and AST offsets; the live converter above follows current daylight saving.
Convert JST to AST Time Zone
Below are the answers people search for most when converting Japan Standard Time (JST) to Atlantic Standard Time (AST).
How does the JST to AST converter work?
It takes three quick steps:
- Click the JST field on the left and pick the time you want to convert.
- The matching AST time updates on the right automatically — there’s no button to press.
- Need a different day? Click the date field and the result follows, rolling over if it crosses midnight.
JST vs AST: what's the time gap?
AST is 13 hours behind JST. In everyday terms, once you know the time on one side you just subtract 13 hours to get the other — so a call between Tokyo and Halifax is always 13 hours apart.
What time is it in AST right now?
Right now the time in Atlantic Standard Time (AST) is Monday, June 29, 2026 · 1:54:04 PM. It ticks every second, so you’re always looking at the live AST clock.
What time is it in JST right now?
And in Japan Standard Time (JST), it’s currently Tuesday, June 30, 2026 · 2:54:04 AM. Compare the two and the 13 hours gap is easy to see.
Planning a meeting across JST and AST?
For example, a 9:00 AM JST meeting takes place at 8:00 PM AST (−1 day). The trick is to aim for a slot that lands inside normal working hours on both sides. Once you’ve found a time, hit Share on the converter to copy a link with the time built in — easy to send to a colleague. Juggling three or more zones? The meeting planner highlights the hours that overlap for everyone.
How does daylight saving affect JST to AST?
The labels JST and AST are fixed offsets, so the result on this page is always exact. One side switches between standard and summer time while the other stays put, so the real-world gap can shift by an hour for part of the year. It's worth checking which label a region is actually using before you lock in a time.
Why can you trust this JST to AST converter?
Every conversion here is calculated from the IANA time zone database — the same source your phone, computer, and browser rely on. Plenty of tools hard-code a single offset, which quietly goes wrong whenever a region changes its rules or flips for daylight saving. We follow the real rules instead, so JST to AST stays accurate for today and for any past or future date you type in.
Convert JST to other time zones
- UTC Coordinated Universal Time
- GMT Greenwich Mean Time
- EST Eastern Standard Time
- EDT Eastern Daylight Time
- CST Central Standard Time
- CDT Central Daylight Time
- MST Mountain Standard Time
- MDT Mountain Daylight Time
- PST Pacific Standard Time
- PDT Pacific Daylight Time
- AKST Alaska Standard Time
- AKDT Alaska Daylight Time
- HST Hawaii Standard Time
- AST Atlantic Standard Time
- ADT Atlantic Daylight Time
- NST Newfoundland Standard Time
- NDT Newfoundland Daylight Time
- BRT Brasília Time
- ART Argentina Time
- WET Western European Time
- WEST Western European Summer Time
- CET Central European Time
- CEST Central European Summer Time
- EET Eastern European Time
- EEST Eastern European Summer Time
- BST British Summer Time
- IST Irish Standard Time
- MSK Moscow Standard Time
- TRT Turkey Time
- WAT West Africa Time
- CAT Central Africa Time
- EAT East Africa Time
- SAST South Africa Standard Time
- GST Gulf Standard Time
- IST Israel Standard Time
- IDT Israel Daylight Time
- IST India Standard Time
- PKT Pakistan Standard Time
- BDT Bangladesh Standard Time
- ICT Indochina Time
- WIB Western Indonesian Time
- WITA Central Indonesian Time
- WIT Eastern Indonesian Time
- CST China Standard Time
- HKT Hong Kong Time
- SGT Singapore Time
- PHT Philippine Time
- KST Korea Standard Time
- AWST Australian Western Standard Time
- ACST Australian Central Standard Time
- ACDT Australian Central Daylight Time
- AEST Australian Eastern Standard Time
- AEDT Australian Eastern Daylight Time
- NZST New Zealand Standard Time
- NZDT New Zealand Daylight Time
Convert to AST from other time zones
- UTC Coordinated Universal Time
- GMT Greenwich Mean Time
- EST Eastern Standard Time
- EDT Eastern Daylight Time
- CST Central Standard Time
- CDT Central Daylight Time
- MST Mountain Standard Time
- MDT Mountain Daylight Time
- PST Pacific Standard Time
- PDT Pacific Daylight Time
- AKST Alaska Standard Time
- AKDT Alaska Daylight Time
- HST Hawaii Standard Time
- ADT Atlantic Daylight Time
- NST Newfoundland Standard Time
- NDT Newfoundland Daylight Time
- BRT Brasília Time
- ART Argentina Time
- WET Western European Time
- WEST Western European Summer Time
- CET Central European Time
- CEST Central European Summer Time
- EET Eastern European Time
- EEST Eastern European Summer Time
- BST British Summer Time
- IST Irish Standard Time
- MSK Moscow Standard Time
- TRT Turkey Time
- WAT West Africa Time
- CAT Central Africa Time
- EAT East Africa Time
- SAST South Africa Standard Time
- GST Gulf Standard Time
- IST Israel Standard Time
- IDT Israel Daylight Time
- IST India Standard Time
- PKT Pakistan Standard Time
- BDT Bangladesh Standard Time
- ICT Indochina Time
- WIB Western Indonesian Time
- WITA Central Indonesian Time
- WIT Eastern Indonesian Time
- CST China Standard Time
- HKT Hong Kong Time
- SGT Singapore Time
- PHT Philippine Time
- JST Japan Standard Time
- KST Korea Standard Time
- AWST Australian Western Standard Time
- ACST Australian Central Standard Time
- ACDT Australian Central Daylight Time
- AEST Australian Eastern Standard Time
- AEDT Australian Eastern Daylight Time
- NZST New Zealand Standard Time
- NZDT New Zealand Daylight Time
Frequently asked questions
How many hours behind JST is AST?
AST is 13 hours behind JST — a fixed 13 hours difference, since both are fixed-offset labels.
What time is it in AST when it's 12:00 PM JST?
When it's 12:00 PM (noon) JST, it's 11:00 PM AST the previous day.
Do JST or AST use daylight saving time?
Japan Standard Time (JST) is a fixed offset with no daylight saving; Atlantic Standard Time (AST) observes daylight saving, alternating with ADT.
Why might the real-world JST–AST difference change during the year?
The labels JST and AST are fixed offsets, so this converter is always exact. But Atlantic Standard Time's region switches between standard and summer time, so for part of the year you may actually want JST to ADT. Always check which label a region is currently using before you schedule.