Time in Chicago, the Central clock.

Chicago is on Central Time. That is Central Standard Time, CST, UTC-6, in winter and Central Daylight Time, CDT, UTC-5, in summer. The big clock shows the time in Chicago to the second, and the cards under it give the zone, the UTC offset, the next clock change and your gap to the city. Chicago is the usual city people pick for "Central time", and the name CT covers both halves of the year.

How to use this Chicago time page

1. Read the big clock: hours, minutes and seconds in Chicago, then the date, the name of the zone and its UTC offset.
2. The cards under it show the time zone, the UTC offset, whether the place changes its clocks and when next, and the difference from your own time zone. If the page has guessed your zone wrong, pick the right one under Your place.
3. To plan a call, set a Date and a Time under What time is it there when it is. The line under the boxes gives the time in Chicago, with the day. Use now sets your own current time.
4. The row of eight times below shows common hours of your day, every three hours, next to the matching time there.
5. On the right, tick 24-hour clock or switch Show seconds off. Copy the time copies one line you can paste into a message. Your choices stay in this browser.

What the official sources say

Section 71.6 puts the Central zone between two lines: the Eastern and Central line in section 71.5 and the Central and Mountain line in section 71.7. The Illinois-Indiana part of section 71.5(b) places the line along the northern edge of Indiana to the east line of LaPorte County, then south through Starke, Marshall, Pulaski and Jasper counties, so the corner of northwest Indiana beside Chicago is Central too, while the rest of Indiana east of that line is Eastern. Illinois itself lies west of the line, on the Central side. Checked 24 Oct 2026.

When the clocks change

Under 49 CFR section 71.2, standard time is advanced one hour at 2 a.m. on the second Sunday in March, and the advance ends at 2 a.m. on the first Sunday in November. A state may exempt itself, and this one does not. In 2026 the dates are Sunday 8 March and Sunday 1 November. In 2027 they are Sunday 14 March and Sunday 7 November.

The cards above give the next change from your browser's own data. Dates in the table come from the IANA database, version 2026e, read on 24 Oct 2026.

Chicago against the cities around it

Chicago, Milwaukee, St. Louis and Dallas share one clock. Indianapolis is one hour ahead, because most of Indiana is east of the line in section 71.5(b). If you drive east from Chicago into Indiana, the clock you need depends on the county, so check before you book a time there.

CST or CT

CST is only right in winter, because in summer the Chicago clock is on CDT. If you need a name that is right all year, write CT. For pairs see CST to EST.

Chicago compared with other places

The gap with London through 2026

The two places do not change their clocks on the same days, so the gap is not one number. Each row starts on the day the gap changes, by the clock in Chicago. The change happens at a set hour that day, so use the box above for an exact time.

A worked example

Take a 9:00 AM call in Chicago and ask what time it is in London.

• In July, 9:00 AM on Tue 14 Jul in Chicago is 2:00 PM UTC on Tue 14 Jul (9:00 AM plus 5 h). London is on UTC+1, so the same moment is 3:00 PM on Tue 14 Jul there.
• In January, 9:00 AM on Tue 13 Jan in Chicago is 3:00 PM UTC on Tue 13 Jan (9:00 AM plus 6 h). London is on UTC+0, so the same moment is 3:00 PM on Tue 13 Jan there.

Shared working hours

If both sides work 9:00 AM to 5:00 PM, this is the window in which both are at their desks, on a Tuesday in January and a Tuesday in July 2026.

Sources, checked 24 Oct 2026. 49 CFR Part 71, Standard Time Zone Boundaries; the IANA time zone database (version 2026e).

Related: CST to EST, time in Texas and the time zone converter.