What is the difference between CST and CDT?

CDT is daylight saving time: clocks move forward one hour in spring. CST (UTC−6) applies from the first Sunday in November to the second Sunday in March; CDT (UTC−5) applies the rest of the year.

When does CDT start and end?

In the US, daylight saving time starts at 2:00 AM on the second Sunday in March and ends at 2:00 AM on the first Sunday in November.

Is it CST or CDT right now?

Between mid-March and early November it is CDT; the rest of the year it is CST. Many people write “CT” (e.g. ET, CT) to mean whichever is currently in effect.

CDT to CST Time

Instantly convert Central Daylight Time (CDT) to Central Standard Time (CST) for precise scheduling of professional, educational, or personal events while considering daylight saving changes.

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Updated Sep 2026

In short

CST is 1 hour behind CDT. CST (UTC−6) and CDT (UTC−5) are the winter and summer times of the same US region, so a clock showing 10:20 PM CDT reads 9:20 PM CST.

How it works

CDT and CST are the same place — US Central — at different times of year. CST is standard time, used from early November to mid-March; CDT is daylight saving time, used from mid-March to early November. They are exactly one hour apart.

Take the CDT time.
Subtract one hour.
That is the same moment written as CST.

Clocks go forward on the second Sunday in March at 2 a.m. local time and back on the first Sunday in November. On those two days one hour is skipped or repeated, which is why appointment times around 2 a.m. can look strange.

Writing “Central Time” or the city name avoids the problem entirely: it means whichever of the two is in force on that date. The converter above does that automatically.

Examples

The same moment, written both ways:

CDT and CST
CDT	CST
09:00	08:00
12:00	11:00
17:30	16:30
23:00	22:00

Only one of the two labels is correct on any given date, so a meeting invite in CDT during winter is usually a mistake for CST.

CDT to CST Time: frequently asked questions

What is the difference between CST and CDT?: CDT is daylight saving time: clocks move forward one hour in spring. CST (UTC−6) applies from the first Sunday in November to the second Sunday in March; CDT (UTC−5) applies the rest of the year.
When does CDT start and end?: In the US, daylight saving time starts at 2:00 AM on the second Sunday in March and ends at 2:00 AM on the first Sunday in November.
Is it CST or CDT right now?: Between mid-March and early November it is CDT; the rest of the year it is CST. Many people write “CT” (e.g. ET, CT) to mean whichever is currently in effect.