What is the time difference between Sydney and Chicago?

Chicago is 15 hours behind Sydney. 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 Chicago from Sydney?

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 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.

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.

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

It is 21:00 in Chicago, still on the previous day. That holds for the current offsets; it shifts by an hour around the daylight saving dates listed above.

Which time zones do Sydney and Chicago use?

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

Convert Sydney time to Chicago time

Chicago is 15 hours behind Sydney right now, so midday in Sydney lands in the evening in Chicago.

Convert a time

From

Date

Time

Converted time

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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

The whole day mapped across: read down the left for Sydney, across for Chicago.

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

Daylight saving time

Both cities change their clocks, but not necessarily on the same date — which is why the difference between them shifts for a few weeks each year.

Sydney

Observes daylight saving time

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

Chicago

Observes daylight saving time

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

When you can actually talk

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

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

Reference

The underlying data, in case you need to put it in a calendar invitation or a configuration file.

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

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

Common questions

What is the time difference between Sydney and Chicago?: Chicago is 15 hours behind Sydney. 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 Chicago from Sydney?: 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 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.
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.
If it is midday in Sydney, what time is it in Chicago?: It is 21:00 in Chicago, still on the previous day. That holds for the current offsets; it shifts by an hour around the daylight saving dates listed above.
Which time zones do Sydney and Chicago use?: Sydney uses Australia/Sydney, currently UTC+10 (AEST), and Chicago uses America/Chicago, currently UTC-5 (CDT). Those identifiers are the ones to use in code — abbreviations are ambiguous and offsets change.