Sydney is 15 to 17 hours ahead of Chicago, depending on the time of year. If you are both awake 7 am to 11 pm, a January weekday gives you 9 hours awake at the same time, though none of them is outside a 9-to-5 for both of you (in July: 8 hours shared, 2 hours free). Here are the good ones.
Sydney is 17 hours ahead of Chicago that week. On a weekday you are both awake for 9 hours, but none of them is outside work for both of you, so a lunch break or a commute has to do the work.
Worked out for the week of 11 January 2027 (11 Jan – 17 Jan), in Chicago time, with each zone’s own daylight-saving rules for those dates. Sydney awake 7 am – 11 pm, working 9 am – 5 pm weekdays; Chicago awake 7 am – 11 pm, working 9 am – 5 pm weekdays.
A weekday, in Chicago timeboth awake
Chicagoawake 7 am – 11 pm
Sydneyawake 2 pm – 6 am Chicago time
7a10a1p4p7p10p1a4a7a
Best on a weekday
7 – 9 pm Chicago
noon – 2 pm Sydney · Chicago evening, Sydney lunchtime (their next day) · during Sydney’s lunch break
Another weekday option
2 – 4 pm Chicago
7 – 9 am Sydney · Chicago afternoon, Sydney morning (their next day) · during Chicago’s work hours
The long weekend call
Sat 6 – 9 pm Chicago
Sun 11 am – 2 pm Sydney · Chicago early evening, Sydney lunchtime
The week · Chicago time, 11 Jan – 17 Jan
7a
8a
9a
10a
11a
12p
1p
2p
3p
4p
5p
6p
7p
8p
9p
10p
Mon
12a
1a
2a
3a
4a
5a
6a
7a
8a
9a
10a
11a
12p
1p
2p
3p
Tue
12a
1a
2a
3a
4a
5a
6a
7a
8a
9a
10a
11a
12p
1p
2p
3p
Wed
12a
1a
2a
3a
4a
5a
6a
7a
8a
9a
10a
11a
12p
1p
2p
3p
Thu
12a
1a
2a
3a
4a
5a
6a
7a
8a
9a
10a
11a
12p
1p
2p
3p
Fri
12a
1a
2a
3a
4a
5a
6a
7a
8a
9a
10a
11a
12p
1p
2p
3p
Sat
12a
1a
2a
3a
4a
5a
6a
7a
8a
9a
10a
11a
12p
1p
2p
3p
Sun
12a
1a
2a
3a
4a
5a
6a
7a
8a
9a
10a
11a
12p
1p
2p
3p
Columns are Chicago hours; the small figure in each cell is the time in Sydney. both freeboth awake, one at workSydney asleep
The Sydney–Chicago gap through 2027
Dates
Difference
1 January – 13 March
Sydney is 17 hours ahead of Chicago
14 March – 3 April
Sydney is 16 hours ahead of Chicago
4 April – 2 October
Sydney is 15 hours ahead of Chicago
3 October – 6 November
Sydney is 16 hours ahead of Chicago
7 November – 31 December
Sydney is 17 hours ahead of Chicago
The week grid and call windows were worked out for 11 Jan to 17 Jan 2027 with the IANA time-zone rules for Australia/Sydney (Sydney) and America/Chicago (Chicago). That week Chicago is on standard time and Sydney is on daylight-saving (summer) time. The table uses the same rules for every day of 2027. The finder above recalculates for the current week in your browser.
When it is … in Chicago
In Chicago
Sydney, January
Sydney, July
7 am
midnight (next day)
10 pm
9 am
2 am (next day)
midnight (next day)
11 am
4 am (next day)
2 am (next day)
1 pm
6 am (next day)
4 am (next day)
3 pm
8 am (next day)
6 am (next day)
5 pm
10 am (next day)
8 am (next day)
7 pm
noon (next day)
10 am (next day)
9 pm
2 pm (next day)
noon (next day)
Wednesday times. Send times as “your 8 pm” or “my 8 pm” so nobody has to guess whose clock you mean.
Stop doing the math every day
The Long Goodbye keeps your person’s local time and time of day on your home-screen widget and lock screen, so you can see whether it is morning coffee or midnight in Sydney before you call. A “thinking of you” tap lights up their widget, and a countdown keeps the next visit in view.
What is the time difference between Sydney and Chicago?
Sydney is 15 to 17 hours ahead of Chicago, depending on the time of year. In 2027 it is 17 hours from 1 January to 13 March and from 7 November to 31 December; 16 hours from 14 March to 3 April and from 3 October to 6 November; 15 hours from 4 April to 2 October.
What is the best time to call Sydney from Chicago?
In January, the easiest two hours on a weekday are 7 – 9 pm Chicago, which is noon – 2 pm Sydney: Chicago evening, Sydney lunchtime, the next day there, during Sydney’s lunch break. At the weekend, Sat 6 – 9 pm Chicago (Sun 11 am – 2 pm Sydney) gives you a longer call. Change the awake and work hours in the finder on this page to fit your own days.
How many waking hours do Sydney and Chicago share?
If both of you are awake from 7 am to 11 pm, you share 9 hours on a January weekday, but none of them falls outside 9-to-5 working hours in both places; in July it is 8 hours shared and 2 hours free.
Does daylight saving time change the call times?
Yes. In 2027 Chicago changes its clocks on 14 March and 7 November and Sydney changes its clocks on 4 April and 3 October, so a call you keep at the same time in Chicago moves by an hour in Sydney on those dates. Check the table on this page and agree the new time out loud after each change.