CAST to JST Converter
Start by searching for a time zone, city, or town.
Add one or more places to compare local times, adjust the date, and share the result.
Quick answers
Selected conversion
8:00 pm20:00 CAST (UTC+8), Nov 8, 2026 = 9:00 pm21:00 JST (UTC+9), Nov 8, 2026
CAST is 1 hour behind JST.
CAST and JST examples
These examples always use CAST (UTC+8) and JST (UTC+9). They stay the same when you change the date or time above. The selected conversion may differ when daylight saving time applies.
CAST is 1 hour behind JST.
How the time difference changes
CAST is 1 hour behind JST year-round.
Working hours of 9:00 am to 6:00 pm in CAST correspond to 10:00 am to 7:00 pm in JST.Working hours of 09:00 to 18:00 in CAST correspond to 10:00 to 19:00 in JST.
Compare CAST time with JST time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.
Time Difference
Casey Time is 1 hour behind Japan Standard Time.
8:00 pm20:00 in CAST is 9:00 pm21:00 in JST
CAST to JST call time
Best time for a conference call or a meeting is between 9am-5pm09:00-17:00 in CAST which corresponds to 10am-6pm10:00-18:00 in JST.
8:00 pm20:00 Casey Time (CAST). Offset UTC +8:00 hours
9:00 pm21:00 Japan Standard Time (JST). Offset UTC +9:00 hours
8:00 pm20:00 CAST / 9:00 pm21:00 JST
Choose an hour to update the converter. Day labels such as “next day” or “+1” are relative to the selected date in the first column. Use Up and Down arrow keys, Home or End to move between hours, then Enter or Space to select.
| CAST | JST |
|---|---|
| 1:00am | |
| 2:00am | |
| 3:00am | |
| 4:00am | |
| 5:00am | |
| 6:00am | |
| 7:00am | |
| 8:00am | |
| 9:00am | |
| 10:00am | |
| 11:00am | |
| 12:00pm | |
| 1:00pm | |
| 2:00pm | |
| 3:00pm | |
| 4:00pm | |
| 5:00pm | |
| 6:00pm | |
| 7:00pm | |
| 8:00pm | |
| 9:00pm | |
| 10:00pm | |
| 11:00pm | |
| 12:00am next day | |
| 01:00 | |
| 02:00 | |
| 03:00 | |
| 04:00 | |
| 05:00 | |
| 06:00 | |
| 07:00 | |
| 08:00 | |
| 09:00 | |
| 10:00 | |
| 11:00 | |
| 12:00 | |
| 13:00 | |
| 14:00 | |
| 15:00 | |
| 16:00 | |
| 17:00 | |
| 18:00 | |
| 19:00 | |
| 20:00 | |
| 21:00 | |
| 22:00 | |
| 23:00 | |
| 00:00 next day |
Casey Time
Offset: CAST is 8 hours ahead of Greenwich Mean Time (GMT).
Countries using this time zone: Antarctica
Daylight Saving: Clocks in Casey Time (CAST) do not change for daylight saving time, so CAST stays the same throughout the year. Other time zones may set clocks forward in summer and back in winter; see upcoming clock changes worldwide.
CAST representations, usage and related time zones
- +08 - basic short
- +0800 - basic
- +08:00 - extended
- +0800 - sign character (+) followed by a four digit time providing hours (08) and minutes (00) of the offset. Indicates an offset of eight hours to the east of the zero meridian.
- Hotel - Military abbreviation for CAST
- H - short form of 'Hotel'
- ACT - ASEAN Common Time
- AWST - Australian Western Standard Time
- BNT - Brunei Darussalam Time
- CAST - Casey Time
- CHOT - Choibalsan Time
- CST - China Standard Time
- H - Hotel Time Zone
- HKT - Hong Kong Time
- HOVST - Hovd Summer Time
- IRKT - Irkutsk Time
- KRAST - Krasnoyarsk Summer Time
- MYT - Malaysia Time
- PHT - Philippine Time
- SGT - Singapore Time
- ULAT - Ulaanbaatar Time
- WITA - Central Indonesian Time
Japan Standard Time
Offset: JST is 9 hours ahead of Greenwich Mean Time (GMT).
Countries using this time zone: Japan
Principal Cities: The largest city in the JST time zone is Tokyo in Japan, with about 9.733 million people. Other major cities in this time zone include Yokohama, Osaka, Nagoya, Sapporo.
Daylight Saving: Clocks in Japan Standard Time (JST) do not change for daylight saving time, so JST stays the same throughout the year. Other time zones may set clocks forward in summer and back in winter; see upcoming clock changes worldwide.
Current time in Japan: Japan time now
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 an offset of nine hours 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