CST/CDT
Central Standard Time
GMT -6
12am
3am
6am
9am
12pm
3pm
6pm
9pm
CDT is not used on this date
This converter uses CST (GMT -6), the offset Chicago uses on this date. Open the CST converter.
AST
Arabia Standard Time
GMT +3
12am
3am
6am
9am
12pm
3pm
6pm
9pm

Compare CDT time with AST time, including current local time, UTC offsets, time difference, daylight saving changes, working hours, and shareable meeting times.

Time Difference

Central Standard Time is 9 hours behind Arabia Standard Time
6:00 am06:00 in CST is 3:00 pm15:00 in AST

CST to AST call time
Best time for a conference call or a meeting is between 8am-9am in CST which corresponds to 5pm-6pm in AST

6:00 am06:00 Central Standard Time (CST). Offset UTC -6:00 hours
3:00 pm15:00 Arabia Standard Time (AST). Offset UTC +3:00 hours

6:00 am06:00 CST / 3:00 pm15:00 AST

CSTAST
12am (midnight)9am
1am10am
2am11am
3am12pm (noon)
4am1pm
5am2pm
6am3pm
7am4pm
8am5pm
9am6pm
10am7pm
11am8pm
12pm (noon)9pm
1pm10pm
2pm11pm
3pm12am (midnight)
4pm1am
5pm2am
6pm3am
7pm4am
8pm5am
9pm6am
10pm7am
11pm8am
00:0009:00
01:0010:00
02:0011:00
03:0012:00
04:0013:00
05:0014:00
06:0015:00
07:0016:00
08:0017:00
09:0018:00
10:0019:00
11:0020:00
12:0021:00
13:0022:00
14:0023:00
15:0000:00
16:0001:00
17:0002:00
18:0003:00
19:0004:00
20:0005:00
21:0006:00
22:0007:00
23:0008:00

Central Daylight Time

Offset: CDT is 5 hours behind Greenwich Mean Time (GMT) and is used in North America

Countries using this time zone: Canada, Mexico, United States

Principal Cities: The largest city in the CDT time zone is Chicago in the United States, with about 2.696 million people. Other major cities in this time zone include Houston, Ciudad Juarez, San Antonio, Dallas.

French: HAC - Heure Avancée du Centre

Spanish: CT - Zona Centro

CDT Time Zone Geo Map
CDT timezone map

Daylight Saving: Central Daylight Time (CDT) is a daylight saving/summer time zone, but some places set clocks back one hour during winter and observe Central Standard Time (CST).

Daylight saving time clock moves forward for one hour from 2am to 3amEnd: Central Daylight Time (CDT) ended on Sunday, November 2, 2025 at 2:00 am local time and clocks were set one hour back to Sunday, November 2, 2025, 1:00 am local standard time instead. Daylight saving ends annually on the first Sunday of November

Daylight saving time clock moves back for one hour from 2am to 1amStart: Central Daylight Time (CDT) starts on Sunday, March 8, 2026 at 2:00 am local time and clocks are set one hour forward to Sunday, March 8, 2026, 3:00 am. Daylight saving starts annually on the second Sunday of March

CDT representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • -05 - basic short
  • -0500 - basic
  • -05:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • -0500 - sign character (-) followed by a four digit time providing hours (05) and minutes (00) of the offset. Indicates an offset of five hours to the west of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Romeo - Military abbreviation for CDT
  • R - short form of 'Romeo'
IANA/Olson: Reflects CDT time zone boundaries defined by political bodies, primarily intended for use with computer programs and operating systems
  • America/Chicago
  • America/Indiana/Knox
  • America/Indiana/Tell_City
  • America/Knox_IN
  • America/Matamoros
  • America/Menominee
  • America/North_Dakota/Beulah
  • America/North_Dakota/Center
  • America/North_Dakota/New_Salem
  • America/Ojinaga
  • America/Rainy_River
  • America/Rankin_Inlet
  • America/Resolute
  • America/Winnipeg
  • CST6CDT
  • Canada/Central
  • US/Central
  • US/Indiana-Starke
CDT Abbreviation: Several time zones share CDT abbreviation and it could refer to these time zones
  • Central Daylight Time - UTC -5
  • Cuba Daylight Time - UTC -4
Time zones with the GMT -5 offset:
  • CDT - Central Daylight Time
  • EST - Eastern Standard Time
  • ET - Eastern Time
  • COT - Colombia Time
  • CST - Cuba Standard Time
  • EASST - Easter Island Summer Time
  • ECT - Ecuador Time
  • PET - Peru Time
  • R - Romeo Time Zone

Arabia Standard Time

Offset: AST is 3 hours ahead Greenwich Mean Time (GMT) and is used in Asia

Countries using this time zone: Saudi Arabia

Principal Cities: The largest city in the AST time zone is Riyadh in Saudi Arabia, with about 4.206 million people. Other major cities in this time zone include Jeddah, Mecca, Medina, Sultanah.

Daylight Saving: Clocks in Arabia Standard Time (AST) do not change for daylight saving time, so AST stays the same throughout the year. Other time zones may set clocks forward in summer and back in winter.

AST Time Zone Geo Map
AST timezone map

AST representations, usage and related time zones

W3C/ISO-8601: International standard covering representation and exchange of dates and time-related data
  • +03 - basic short
  • +0300 - basic
  • +03:00 - extended
Email/RFC-2822: Internet Message Format Date Standard, typically used for timestamps in email headers
  • +0300 - sign character (+) followed by a four digit time providing hours (03) and minutes (00) of the offset. Indicates an offset of three hours to the east of the zero meridian.
Military/NATO: Used by the U.S. military, Chinese military and others
  • Charlie - Military abbreviation for AST
  • C - short form of 'Charlie'
AST Abbreviation: Several time zones share AST abbreviation and it could refer to these time zones
  • Atlantic Standard Time - UTC -4
  • Arabia Standard Time - UTC +3
Time zones with the GMT +3 offset:
  • EEST - Eastern European Summer Time
  • MSK - Moscow Standard Time
  • AST - Arabia Standard Time
  • C - Charlie Time Zone
  • EAT - Eastern Africa Time
  • FET - Further Eastern European Time
  • IDT - Israel Daylight Time
  • TRT - Turkey Time