Time difference between Chicago and Sydney
Good time for both on a weekday: 16:00–17:00 in Chicago = 9:00–10:00 in Sydney.
- Everyone at work
- Work hours
- Awake
- Night
- Weekend
Tap any column to see that moment in every city.
Different hours for each city
- 15–17 hoursSydney ahead of Chicago
- UTC−6 / UTC−5Chicago, January / July
- UTC+11 / UTC+10Sydney, January / July
- 1 hour / 0 hoursshared 9-to-5 time, January / July
How the gap moves through the year
Sydney is 15 hours ahead of Chicago for about 6 months of the year.
Sydney is 17 hours ahead of Chicago for about 4 months of the year.
Sydney is 16 hours ahead of Chicago for about 8 weeks of the year.
The short odd stretches come from the two cities changing their clocks on different weekends.
From the second Sunday in March (when Chicago moves forward), Sydney is 16 hours ahead of Chicago.
From the first Sunday in April (when Sydney falls back), Sydney is 15 hours ahead of Chicago.
From the first Sunday in October (when Sydney moves forward), Sydney is 16 hours ahead of Chicago.
From the first Sunday in November (when Chicago falls back), Sydney is 17 hours ahead of Chicago.
Chicago moves its clocks forward one hour on the second Sunday in March at 2:00 am local time and back on the first Sunday in November at 2:00 am, switching between Central Standard Time (UTC−6) and Central Daylight Time (UTC−5).
Sydney moves its clocks forward one hour on the first Sunday in October at 2:00 am local time and back on the first Sunday in April at 3:00 am, switching between Australian Eastern Standard Time (UTC+10) and Australian Eastern Daylight Time (UTC+11).
Next clock change for this pair, as of when this page was built (2026-10-20): Chicago falls back on Sun 1 November 2026.
Everything on this page also holds if you swap Chicago for Houston, San Antonio, Dallas, Austin or Winnipeg, or Sydney for Melbourne, Canberra or Hobart — those cities follow exactly the same clock all year.
Working hours that overlap
In January, a 9-to-5 day in both cities shares 1 hour: 4:00 pm–5:00 pm in Chicago, which is 9:00 am–10:00 am in Sydney.
In July, two 9-to-5 days never meet — not a single quarter-hour is inside working hours in both cities.
Stretching both days to 8:00–18:00 opens 1 hour (5:00 pm–6:00 pm in Chicago). Beyond that, one side has to take an early-morning or evening call.
Across the week
At 9:00 on a Monday morning in Chicago, it is 2:00 am on Tuesday in Sydney — already a day ahead there.
8 hours of a Chicago working week (Monday to Friday, 9 to 5) fall on the weekend in Sydney, so part of Monday or Friday is lost for meetings.
Daylight, distance and night calls
Chicago and Sydney are about 14,870 km (9,240 miles) apart and 121° of longitude apart, which by the sun alone would be 8 hours.
Chicago's winter clock runs 9 minutes behind the sun, and Sydney's runs 55 minutes ahead of the sun.
In mid-January the sun is up in Chicago from about 7:16 am to 4:43 pm, and the sun is up in Sydney from about 5:59 am to 8:09 pm; both cities are in daylight at the same time for about 3 hours 45 minutes.
In mid-July the sun is up in Chicago from about 5:28 am to 8:25 pm, and the sun is up in Sydney from about 6:58 am to 5:04 pm; both cities are in daylight at the same time for about 4 hours 30 minutes.
In January, 4 hours of a Chicago office day fall in Sydney's night (10 pm to 6 am), and 2 hours of a Sydney office day fall in Chicago's night.
In July, 6 hours of a Chicago office day fall in Sydney's night (10 pm to 6 am), and 4 hours of a Sydney office day fall in Chicago's night.
Hour-by-hour table and common mistakes — 2 more sections
| Chicago | Sydney, January | Sydney, July |
|---|---|---|
| 12:00 am | 5:00 pm | 3:00 pm |
| 1:00 am | 6:00 pm | 4:00 pm |
| 2:00 am | 7:00 pm | 5:00 pm |
| 3:00 am | 8:00 pm | 6:00 pm |
| 4:00 am | 9:00 pm | 7:00 pm |
| 5:00 am | 10:00 pm | 8:00 pm |
| 6:00 am | 11:00 pm | 9:00 pm |
| 7:00 am | 12:00 am (+1 day) | 10:00 pm |
| 8:00 am | 1:00 am (+1 day) | 11:00 pm |
| 9:00 am | 2:00 am (+1 day) | 12:00 am (+1 day) |
| 10:00 am | 3:00 am (+1 day) | 1:00 am (+1 day) |
| 11:00 am | 4:00 am (+1 day) | 2:00 am (+1 day) |
| 12:00 pm | 5:00 am (+1 day) | 3:00 am (+1 day) |
| 1:00 pm | 6:00 am (+1 day) | 4:00 am (+1 day) |
| 2:00 pm | 7:00 am (+1 day) | 5:00 am (+1 day) |
| 3:00 pm | 8:00 am (+1 day) | 6:00 am (+1 day) |
| 4:00 pm | 9:00 am (+1 day) | 7:00 am (+1 day) |
| 5:00 pm | 10:00 am (+1 day) | 8:00 am (+1 day) |
| 6:00 pm | 11:00 am (+1 day) | 9:00 am (+1 day) |
| 7:00 pm | 12:00 pm (+1 day) | 10:00 am (+1 day) |
| 8:00 pm | 1:00 pm (+1 day) | 11:00 am (+1 day) |
| 9:00 pm | 2:00 pm (+1 day) | 12:00 pm (+1 day) |
| 10:00 pm | 3:00 pm (+1 day) | 1:00 pm (+1 day) |
| 11:00 pm | 4:00 pm (+1 day) | 2:00 pm (+1 day) |
Common mistakes with Chicago and Sydney
- Assuming the gap is fixed. Both cities change their clocks, but not on the same weekend, so a recurring meeting can land an hour off for a few weeks.
- Getting the date wrong. With a gap this large, an afternoon call in one city is the next morning — or the previous evening — in the other. Write the date for both cities in the invite.
- Writing “CST” all year for Chicago. In summer the zone is Central Daylight Time; calendar apps handle it, but a typed time in an email can be read the wrong way.
Questions
- Is Sydney ahead of Chicago?
- Sydney is 17 hours ahead of Chicago in January and 15 hours ahead of Chicago in July.
- What is a good time for a meeting between Chicago and Sydney?
- With 9-to-5 days in both cities, 4:00 pm–5:00 pm Chicago time is inside working hours in both, which gives 1 hour. The window can shift by an hour in the weeks when only one city has changed its clocks.
- Does the time difference between Chicago and Sydney change?
- Yes. Sydney is 15 hours ahead of Chicago for about 6 months of the year. Sydney is 17 hours ahead of Chicago for about 4 months of the year. Sydney is 16 hours ahead of Chicago for about 8 weeks of the year.
Related time differences
- New York and ChicagoChicago behind by 1 hour · 7 hours of shared office time
- London and ChicagoChicago behind by 6 hours · 2 hours of shared office time
- Los Angeles and ChicagoChicago ahead by 2 hours · 6 hours of shared office time
- Chicago and PhoenixPhoenix behind by 1–2 hours · 7 hours of shared office time
- Chicago and TokyoTokyo ahead by 14–15 hours · no shared office hours
- Chicago and ParisParis ahead by 7 hours · 1 hour of shared office time
- New York and SydneySydney ahead by 14–16 hours · no shared office hours
- London and SydneySydney ahead by 9–11 hours · no shared office hours
- Sydney and SingaporeSingapore behind by 2–3 hours · 6 hours of shared office time
- Sydney and BrisbaneBrisbane behind by 0–1 hours · 8 hours of shared office time
Chicago time zone · Sydney time zone · Plan with more cities
City names, coordinates and time zone assignments: GeoNames, licensed under CC BY 4.0 (selection and renaming of some cities by this site). Clock times are computed in your browser from the IANA time zone database. Sources and limits.