epochkit

CST to UTC converter

UTC is 6 hours ahead of Central Time while Central Time is on CST (UTC−6), and 5 hours ahead while Central Time is on CDT (UTC−5). To convert CST to UTC, add 6 hours in winter and 5 hours in summer.

Central Time CST
--:--:--  
UTC UTC
--:--:--  

Central Time runs at UTC−6 / UTC−5, UTC at UTC+0.

CST to UTC conversion table

Every hour of the day converted for both halves of the year. The two columns differ because Central Time changes its offset for daylight saving time.

Hour-by-hour conversion from Central Time to UTC
Central Time (CST / CDT) UTC (CST, Nov–Mar) UTC (CDT, Mar–Nov)
00:00 12:00 AM 06:00 6:00 AM 05:00 5:00 AM
01:00 1:00 AM 07:00 7:00 AM 06:00 6:00 AM
02:00 2:00 AM 08:00 8:00 AM 07:00 7:00 AM
03:00 3:00 AM 09:00 9:00 AM 08:00 8:00 AM
04:00 4:00 AM 10:00 10:00 AM 09:00 9:00 AM
05:00 5:00 AM 11:00 11:00 AM 10:00 10:00 AM
06:00 6:00 AM 12:00 12:00 PM 11:00 11:00 AM
07:00 7:00 AM 13:00 1:00 PM 12:00 12:00 PM
08:00 8:00 AM 14:00 2:00 PM 13:00 1:00 PM
09:00 9:00 AM 15:00 3:00 PM 14:00 2:00 PM
10:00 10:00 AM 16:00 4:00 PM 15:00 3:00 PM
11:00 11:00 AM 17:00 5:00 PM 16:00 4:00 PM
12:00 12:00 PM 18:00 6:00 PM 17:00 5:00 PM
13:00 1:00 PM 19:00 7:00 PM 18:00 6:00 PM
14:00 2:00 PM 20:00 8:00 PM 19:00 7:00 PM
15:00 3:00 PM 21:00 9:00 PM 20:00 8:00 PM
16:00 4:00 PM 22:00 10:00 PM 21:00 9:00 PM
17:00 5:00 PM 23:00 11:00 PM 22:00 10:00 PM
18:00 6:00 PM 00:00 12:00 AM next day 23:00 11:00 PM
19:00 7:00 PM 01:00 1:00 AM next day 00:00 12:00 AM next day
20:00 8:00 PM 02:00 2:00 AM next day 01:00 1:00 AM next day
21:00 9:00 PM 03:00 3:00 AM next day 02:00 2:00 AM next day
22:00 10:00 PM 04:00 4:00 AM next day 03:00 3:00 AM next day
23:00 11:00 PM 05:00 5:00 AM next day 04:00 4:00 AM next day

How the CST to UTC conversion works

Converting CST to UTC means taking a wall-clock time in Central Time (CST / CDT, UTC−6 / UTC−5) and expressing the same instant in UTC (UTC, UTC+0). The arithmetic is one step: add 6 hours while Central Time is on standard time, and 5 hours while it is on daylight saving time. Applying the gap pushes part of the day onto a different calendar date — the table below marks every row that shifts. In code, store the instant in UTC and convert with the IANA identifiers America/Chicago and Etc/UTC, never with the abbreviations. One note on the source label: CST is also used for China Standard Time (UTC+8) and Cuba Standard Time, so the abbreviation alone is ambiguous. On the target label: UTC is the fixed reference every other offset is measured against, and it never shifts. A bare "09:00" carries no offset and means nothing until you attach the zone it belongs to.

Best time for meetings between CST and UTC

Working hours are taken as 09:00–18:00 in each zone. The window in force depends on the date, so both halves of the year are listed where they differ.

UTC (CST, Nov–Mar)

 

A 9-to-6 working day in both zones overlaps for 3 hours: 9:00 AM–12:00 PM CST is 3:00 PM–6:00 PM UTC. Book inside that window and neither side is working outside normal hours.

UTC (CDT, Mar–Nov)

 

A 9-to-6 working day in both zones overlaps for 4 hours: 9:00 AM–1:00 PM CDT is 2:00 PM–6:00 PM UTC. A call booked inside that window keeps both sides within a normal working day.

Daylight saving time: which side moves

Only Central Time shifts. UTC holds a single offset all year, so every change in the gap comes from Central Time moving between CST (UTC−6) and CDT (UTC−5).

UTC is 6 hours ahead of Central Time through the Nov–Mar window, and 5 hours ahead through the Mar–Nov window.

US daylight saving time runs from the second Sunday in March to the first Sunday in November.

Central Time
America/Chicago
CST / CDT — UTC−6 / UTC−5
UTC
Etc/UTC
UTC — UTC+0

Frequently asked questions

What is the time difference between CST and UTC?

UTC runs 6 hours ahead of Central Time during standard time and 5 hours ahead during daylight saving time. In offset terms, Central Time sits at UTC−6 / UTC−5 and UTC at UTC+0. So 9:00 AM CST is 3:00 PM UTC, while 9:00 AM CDT is 2:00 PM UTC. The hour-by-hour table on this page lists the conversion for all 24 hours so you do not have to do the arithmetic.

Does the CST to UTC difference change with daylight saving time?

The difference does change. Central Time moves its clocks, so the gap swings between 6 hours and 5 hours depending on the date. In the US that means clocks move forward on the second Sunday of March and back on the first Sunday of November. Convert against the IANA rules for the exact date rather than a remembered offset.

What time is 9 am CST in UTC?

9:00 AM CST is 3:00 PM UTC. The same clock reading in summer is CDT, and 9:00 AM CDT is 2:00 PM UTC. The rule is the same one the whole page runs on: add 6 hours in winter and 5 hours in summer. Check the hour-by-hour table for any other starting hour, including the rows that land on the previous or next calendar day.

What do CST and UTC stand for?

CST stands for Central Standard Time, and CDT is Central Daylight Time. UTC stands for Coordinated Universal Time. Both are display labels rather than rules: the offsets behind them come from the IANA identifiers America/Chicago and Etc/UTC. CST is also used for China Standard Time (UTC+8) and Cuba Standard Time, so the abbreviation alone is ambiguous.

Related conversions

Need more than two zones at once? The full timezone converter shows a single moment across up to six IANA timezones, for any date you choose.

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