What is the time difference between Chicago and Sydney?

Sydney is 15 hours ahead of Chicago. That figure is current — it changes by an hour when either city starts or ends daylight saving, and the exact dates are listed above.

When is the best time to call Sydney from Chicago?

There is no time inside normal working hours in both cities, so someone has to take the call outside them. The nearest workable windows are listed above — pick one and alternate who gets the awkward slot.

Does Chicago observe daylight saving time?

Yes. Chicago runs on UTC-6 in winter and UTC-5 in summer. The next change is on 2026-11-01, when clocks go back by 60 minutes.

Does Sydney observe daylight saving time?

Yes. Sydney runs on UTC+10 in winter and UTC+11 in summer. The next change is on 2026-10-04, when clocks go forward by 60 minutes.

If it is midday in Chicago, what time is it in Sydney?

It is 03:00 in Sydney, and already the following day. That holds for the current offsets; it shifts by an hour around the daylight saving dates listed above.

Which time zones do Chicago and Sydney use?

Chicago uses America/Chicago, currently UTC-5 (CDT), and Sydney uses Australia/Sydney, currently UTC+10 (AEST). Those identifiers are the ones to use in code — abbreviations are ambiguous and offsets change.

Convert Chicago time to Sydney time

Right now Sydney runs 15 hours ahead of Chicago. That gap is not fixed: it moves when either city changes its clocks.

Convert a time

From

Date

Time

Converted time

—

The converter needs JavaScript to run. Everything below — offsets, daylight saving dates and the hour-by-hour table — is part of the page and works without it.

Hour by hour

Every hour of a day in Chicago, and what the clock reads in Sydney at that same moment.

Chicago	Sydney
00:00	15:00
01:00	16:00
02:00	17:00
03:00	18:00
04:00	19:00
05:00	20:00
06:00	21:00
07:00	22:00
08:00	23:00
09:00	00:00next day
10:00	01:00next day
11:00	02:00next day
12:00	03:00next day
13:00	04:00next day
14:00	05:00next day
15:00	06:00next day
16:00	07:00next day
17:00	08:00next day
18:00	09:00next day
19:00	10:00next day
20:00	11:00next day
21:00	12:00next day
22:00	13:00next day
23:00	14:00next day

Daylight saving time

Chicago and Sydney both observe daylight saving. Where their change dates differ, so does the gap between them for the weeks in between.

Chicago

Observes daylight saving time

Standard: UTC-6
Daylight: UTC-5
Next change: 2026-11-01 −60m

Sydney

Observes daylight saving time

Standard: UTC+10
Daylight: UTC+11
Next change: 2026-10-04 +60m

When you can actually talk

A standard working day in Chicago and one in Sydney do not overlap at all. Any call between them is early for one side or late for the other.

Chicago 19:00–03:00Sydney 10:00–18:00
Chicago 09:00–19:00Sydney 00:00–10:00

Reference

The zone identifiers and offsets behind everything above.

	Chicago	Sydney
IANA zone	America/Chicago	Australia/Sydney
Abbreviation	CDT	AEST
Standard offset	UTC-6	UTC+10
Daylight offset	UTC-5	UTC+11
Clock changes this year	2	2
Country	United States	Australia

Example, not the current time. Live times appear once the page loads.

Common questions

What is the time difference between Chicago and Sydney?: Sydney is 15 hours ahead of Chicago. That figure is current — it changes by an hour when either city starts or ends daylight saving, and the exact dates are listed above.
When is the best time to call Sydney from Chicago?: There is no time inside normal working hours in both cities, so someone has to take the call outside them. The nearest workable windows are listed above — pick one and alternate who gets the awkward slot.
Does Chicago observe daylight saving time?: Yes. Chicago runs on UTC-6 in winter and UTC-5 in summer. The next change is on 2026-11-01, when clocks go back by 60 minutes.
Does Sydney observe daylight saving time?: Yes. Sydney runs on UTC+10 in winter and UTC+11 in summer. The next change is on 2026-10-04, when clocks go forward by 60 minutes.
If it is midday in Chicago, what time is it in Sydney?: It is 03:00 in Sydney, and already the following day. That holds for the current offsets; it shifts by an hour around the daylight saving dates listed above.
Which time zones do Chicago and Sydney use?: Chicago uses America/Chicago, currently UTC-5 (CDT), and Sydney uses Australia/Sydney, currently UTC+10 (AEST). Those identifiers are the ones to use in code — abbreviations are ambiguous and offsets change.