CST to IST Converter

Convert time between Central Standard Time (CST) and India Standard Time (IST)

Central Standard Time (CST)

20:30:39
UTC +0
Dec 28, 2025
America/Chicago

India Standard Time (IST)

20:30:39
UTC +0
Dec 28, 2025
Asia/Kolkata

Time Difference

India Standard Time (IST) is 0 hours ahead of Central Standard Time (CST)

Select Date

Select Time

Quick Reference

CSTIST
20:0007:30
22:0009:30
00:0011:30
02:0013:30
04:0015:30
06:0017:30
08:0019:30
10:0021:30
12:0023:30
14:0001:30
16:0003:30
18:0005:30

Top 10 Most Common Time Zones

AbbreviationFull NameUTC OffsetTypical Use
UTCCoordinated Universal TimeUTC ±0Global reference standard (servers, logs, APIs)
EST / EDTEastern (US) TimeUTC −5 / −4New York, Toronto — North American business hub
CST / CDTCentral (US) TimeUTC −6 / −5Chicago, Dallas — US central business region
PST / PDTPacific (US) TimeUTC −8 / −7San Francisco, Los Angeles — tech industry standard
GMT / BSTGreenwich Mean / British Summer TimeUTC 0 / +1UK, used globally as a reference with UTC
CET / CESTCentral European (Summer) TimeUTC +1 / +2Paris, Berlin, Amsterdam — EU business core
ISTIndia Standard TimeUTC +5:30India — major IT & outsourcing region
CSTChina Standard TimeUTC +8Beijing, Shanghai — East Asia business hub
JSTJapan Standard TimeUTC +9Tokyo — finance & tech hub
AEST / AEDTAustralian Eastern (Daylight) TimeUTC +10 / +11Sydney, Melbourne — APAC regional business

Why Time Zone Abbreviations Are Ambiguous

Unlike standardized identifiers (like America/New_York or Europe/London from the IANA tz database), abbreviations such as "CST" or "IST" are not globally unique. They can refer to different time zones depending on context — country, region, or even time of year (due to daylight saving time).

Common Ambiguous Time Zone Abbreviations

Abbrev.Common Meaning(s)UTC OffsetRegion(s)
CSTCentral Standard Time / China Standard Time / Cuba Standard TimeUTC−6 / UTC+8 / UTC−5North America, China, Cuba
ISTIndian Standard Time / Irish Standard Time / Israel Standard TimeUTC+5:30 / UTC+1 / UTC+2India, Ireland, Israel
ASTAtlantic Standard Time / Arabia Standard TimeUTC−4 / UTC+3Caribbean, Canada, Middle East
PSTPacific Standard Time / Philippine Standard TimeUTC−8 / UTC+8North America, Philippines
ESTEastern Standard Time (North America / Australia)UTC−5 / UTC+10North America, Australia

✅ Best Practice

To avoid ambiguity, always:

  • Use IANA tz identifiers — e.g., America/New_York instead of "EST"
  • Specify UTC offset explicitly — e.g., UTC−5 when abbreviations must be used
  • Include the full timezone name — e.g., "Eastern Standard Time (EST)" with UTC offset

Related Time Zone Conversions

EST to MST EST to MDT MST to EST MDT to EST MDT to EDT MDT to EET

About CST to IST Time Conversion

Converting time between Central Standard Time (CST) and India Standard Time (IST) is essential for US-India business collaboration. CST is UTC-6, while IST is UTC+5:30, making IST 11.5 hours ahead of CST (approximately 11 hours for practical purposes).

This conversion is vital for coordinating with Indian business partners, software development teams, business process outsourcing operations, and international companies with offices in both the US Midwest and India. Understanding this significant time difference is crucial for scheduling meetings and managing projects across these regions.

Common Use Cases for CST to IST Conversion

Business & Work

  • Scheduling calls with Indian software development teams and IT outsourcing partners
  • Coordinating business operations between US Midwest and India
  • Managing projects with distributed teams across time zones

Personal & Travel

  • Scheduling video calls with friends and family in India
  • Planning travel to India from the Central US region
  • Coordinating with Indian business partners and consultants

Time Zone Information

Central Standard Time (CST)

  • UTC Offset: UTC-6 (UTC-5 during CDT)
  • IANA Timezone: America/Chicago
  • Daylight Saving: Second Sunday in March to First Sunday in November
  • Major Cities: Chicago, Dallas, Houston, Kansas City, Austin, San Antonio
  • Coverage: Central United States and parts of Canada and Mexico

India Standard Time (IST)

  • UTC Offset: UTC+5:30
  • IANA Timezone: Asia/Kolkata
  • Daylight Saving: No daylight saving time
  • Major Cities: New Delhi, Mumbai, Bangalore, Hyderabad, Pune, Kolkata
  • Coverage: Entire India

Quick Reference: CST to IST

8:00 AM CST
7:30 PM IST
12:00 PM CST (noon)
11:30 PM IST
6:00 PM CST
5:30 AM IST (next day)
9:00 PM CST
8:30 AM IST (next day)

Remember: IST is approximately 11.5 hours ahead of CST

Frequently Asked Questions

What is the time difference between CST and IST?

Central Standard Time (CST) is UTC-6, while India Standard Time (IST) is UTC+5:30. IST is 11.5 hours ahead of CST. This means when it's 8:00 AM in CST, it's 7:30 PM the same day in IST.

Does daylight saving time affect CST to IST conversion?

Yes, but only on the US side. When the US observes Central Daylight Time (CDT, UTC-5), the difference becomes 10.5 hours. India does not observe daylight saving time, so IST remains UTC+5:30 year-round. This means the time difference varies depending on whether CST or CDT is active.

What are the best times to schedule meetings between CST and IST zones?

The limited overlap window makes scheduling challenging. Early morning CST (7-9 AM) corresponds to evening IST (6:30-8:30 PM), which is ideal for India. Alternatively, late evening CST (9-11 PM) corresponds to morning IST (8:30-10:30 AM next day). These are the most practical meeting windows for both regions.

What major cities are in CST and IST timezones?

CST covers major US cities like Chicago, Dallas, Houston, Austin, San Antonio, and Kansas City. IST covers all of India, including major cities like New Delhi, Mumbai, Bangalore, Hyderabad, Pune, Chennai, and Kolkata. India uses a single timezone across the entire country.

How do I convert CST to IST manually?

To convert from CST to IST, add 11.5 hours to the CST time. For example, if it's 8:00 AM CST, add 11.5 hours to get 7:30 PM IST the same day. Remember that the difference becomes 10.5 hours when CST transitions to CDT (daylight saving time).

Why is the time difference 11.5 hours instead of a round number?

India Standard Time is UTC+5:30, which includes a 30-minute offset. This was established to ensure the entire country uses a single timezone despite spanning multiple longitudinal degrees. CST is UTC-6, so the total difference is 11.5 hours (5.5 + 6 = 11.5).

Pro Tips

  • • IST is 11.5 hours ahead of CST - a significant time difference that makes same-day scheduling difficult.
  • • India does not observe daylight saving time, so IST remains constant year-round while CST/CDT changes twice annually.
  • • Early morning CST meetings (7-9 AM) work well for India evenings (6:30-8:30 PM) - this is the most popular coordination time.
  • • Late evening CST meetings (10-11 PM) correspond to next morning IST (9:30-10:30 AM) - another viable option for some teams.
  • • When scheduling quarterly or annual meetings, consider that half the year uses CDT (10.5 hour difference) and half uses CST (11.5 hours).
  • • Use 24-hour time format when communicating across CST-IST to avoid confusion with AM/PM, especially across midnight.