AST/ADT to JST time converter

JST is 12 hours ahead of AST/ADT. When it is 9:00 AM in AST/ADT, it is 9:00 PM in JST.

AST/ADT ADT

Friday, October 16, 2026

JST UTC+9

Saturday, October 17, 2026

AST/ADT
Atlantic Standard Time
Fri, Oct 16
ADTUTC-3
JST
Japan Standard Time
Sat, Oct 17
UTC+9+12h
Finding your time zone…
Shared working hours (9:00–18:00)

AST/ADT to JST conversion table

Every hour of today in AST/ADT and the matching time in JST. Light rows are typical working hours (9:00–18:00).

AST/ADTJST
12:00 AM12:00 PM
1:00 AM1:00 PM
2:00 AM2:00 PM
3:00 AM3:00 PM
4:00 AM4:00 PM
5:00 AM5:00 PM
6:00 AM6:00 PM
7:00 AM7:00 PM
8:00 AM8:00 PM
9:00 AM9:00 PM
10:00 AM10:00 PM
11:00 AM11:00 PM
12:00 PM12:00 AM+1 day
1:00 PM1:00 AM+1 day
2:00 PM2:00 AM+1 day
3:00 PM3:00 AM+1 day
4:00 PM4:00 AM+1 day
5:00 PM5:00 AM+1 day
6:00 PM6:00 AM+1 day
7:00 PM7:00 AM+1 day
8:00 PM8:00 AM+1 day
9:00 PM9:00 AM+1 day
10:00 PM10:00 AM+1 day
11:00 PM11:00 AM+1 day

Best time to call or meet

Working hours don't overlap fully. The closest fit is 9:00 AM – 10:00 AM in AST/ADT (9:00 PM – 10:00 PM in JST): working hours on one side, early or late on the other.

Daylight saving time and the difference

The difference changes during the year because AST/ADT and JST switch clocks on different dates:

  • Oct 16, 2026 – Nov 1, 2026: +12h
  • Nov 1, 2026 – Mar 14, 2027: +13h
  • Mar 14, 2027 – Oct 16, 2027: +12h

More conversions

JST to ASTAST to UTCAST to GMTAST to ESTAST to CSTAST to MSTAST to PSTAST to CETAST to MSKAST to GSTAST to PKTAST to ISTAST to SGT
UTC to JSTGMT to JSTEST to JSTCST to JSTMST to JSTPST to JSTCET to JSTMSK to JSTGST to JSTPKT to JSTIST to JSTSGT to JST

Questions and answers

What is the time difference between AST/ADT and JST?

JST is 12 hours ahead of AST/ADT.

What time is it in JST when it is 9 AM in AST/ADT?

When it is 9:00 AM in AST/ADT, it is 9:00 PM in JST.

When is the best time to call JST from AST/ADT?

Working hours don't overlap fully. The closest fit is 9:00 AM – 10:00 AM in AST/ADT (9:00 PM – 10:00 PM in JST): working hours on one side, early or late on the other.

Does the time difference between AST/ADT and JST change?

Yes, for part of the year, because daylight saving time starts and ends on different dates or applies on one side only.