The time difference between Illinois and Tokyo is 15 hours. When it is 12:00 noon in Illinois, it is 03:00 in Tokyo. Illinois uses the America/Chicago time zone (UTC-6), while Tokyo uses Asia/Tokyo (UTC+9).
With a 15 hours gap, there is no standard business-hours overlap between Illinois and Tokyo. One party will need to adjust their schedule. Early mornings in Tokyo or late evenings in Illinois tend to be the most practical compromise.
Use this table to quickly convert any hour from Illinois time to Tokyo time. Rows highlighted in green indicate overlapping business hours in both cities.
| Illinois | Tokyo | |
|---|---|---|
| 00:00 | 15:00 | Night |
| 01:00 | 16:00 | Night |
| 02:00 | 17:00 | Night |
| 03:00 | 18:00 | Night |
| 04:00 | 19:00 | Night |
| 05:00 | 20:00 | Night |
| 06:00 | 21:00 | |
| 07:00 | 22:00 | |
| 08:00 | 23:00 | |
| 09:00 | 00:00 (+1 day) | |
| 10:00 | 01:00 (+1 day) | |
| 11:00 | 02:00 (+1 day) | |
| 12:00 | 03:00 (+1 day) | |
| 13:00 | 04:00 (+1 day) | |
| 14:00 | 05:00 (+1 day) | |
| 15:00 | 06:00 (+1 day) | |
| 16:00 | 07:00 (+1 day) | |
| 17:00 | 08:00 (+1 day) | |
| 18:00 | 09:00 (+1 day) | |
| 19:00 | 10:00 (+1 day) | |
| 20:00 | 11:00 (+1 day) | |
| 21:00 | 12:00 (+1 day) | |
| 22:00 | 13:00 (+1 day) | Night |
| 23:00 | 14:00 (+1 day) | Night |
Neither Illinois nor Tokyo is currently observing daylight saving time. If either city observes DST, the time difference will change by 1 hour when DST begins or ends. Always double-check before scheduling across these time zones during March–April and October–November.
The time difference is 15 hours. Tokyo is 15 hours ahead of Illinois.
It can. If either Illinois or Tokyo observes daylight saving time, the gap will shift by 1 hour during the transition periods (typically March–April and October–November).
There is no ideal window during standard business hours. Consider scheduling at the edges — early morning for the city that is ahead and late afternoon for the city that is behind.
Add 15 hours to Illinois time to get Tokyo time. Use the hour-by-hour table above for a quick reference.