Does it account for Daylight Saving Time?

Yes, our converter uses the IANA timezone database, which includes all current DST rules for every timezone in the world.

UTC (Coordinated Universal Time) is the primary time standard by which the world regulates clocks. All timezones are defined as offsets from UTC.

Can I compare multiple timezones at once?

Yes, you can add multiple cities or timezones and see the equivalent times side by side.

How many timezones are there in the world?

There are 38 distinct UTC offsets in use, ranging from UTC-12 to UTC+14. This includes half-hour (UTC+5:30 India, UTC+9:30 Australia) and 45-minute offsets (UTC+5:45 Nepal, UTC+8:45 Australia).

What is the International Date Line?

The International Date Line (IDL) runs roughly along the 180° meridian in the Pacific Ocean. When you cross it westward, you gain a day; crossing eastward, you lose a day.

Why do some timezones have 30 or 45 minute offsets?

Countries chose offsets that best matched their solar noon. India uses UTC+5:30 and Nepal uses UTC+5:45 because standard hourly offsets didn't align well with their geography.

Which country has the most timezones?

France has the most (12 timezones) due to overseas territories. Russia spans 11 timezones. The US has 6 (including Hawaii and Alaska).

IST to MDT

-11h 30m

IST

ISTSOURCE

UTC+05:30

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

MDT

UTC-06:00☀ DST active

HH12

MM30

00:30 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

IST

MDT

12:00 AM

12:30 PM-1

2:00 AM

2:30 PM-1

4:00 AM

4:30 PM-1

6:00 AM

6:30 PM-1

8:00 AM

8:30 PM-1

10:00 AM

10:30 PM-1

12:00 PM

12:30 AM

2:00 PM

2:30 AM

4:00 PM

4:30 AM

6:00 PM

6:30 AM

8:00 PM

8:30 AM

10:00 PM

10:30 AM

Green rows indicate typical business hours (9 AM - 5 PM)

IST and MDT on the World Map

The map below highlights the IST (India Standard Time) and MDT (Mountain Daylight Time) timezone regions across the globe.

IST Zone

→

MDT Zone

Explore all world timezones interactively →

IST – India Standard Time

UTC+05:30

India Standard Time (IST) is the time zone for India and Sri Lanka, 5 hours and 30 minutes ahead of UTC.

Countries in IST

IndiaSri Lanka

Major Cities in IST

MumbaiDelhiBangaloreKolkataChennaiHyderabadPuneAhmedabadColomboJaipurLucknowSurat

Key Facts about IST

•India is 10 hours 30 minutes ahead of EST and 5 hours 30 minutes ahead of GMT.
•India uses a single time zone despite spanning 30° of longitude.
•IST is one of only a handful of time zones with a 30-minute offset.
•IST is the most populous single time zone in the world with over 1.4 billion people.
•The Bombay Stock Exchange (BSE) and National Stock Exchange (NSE) operate on IST.

Daylight Saving:No – UTC+05:30 year-round

Learn more about IST on Wikipedia

MDT – Mountain Daylight Time

UTC-06:00

Mountain Daylight Time (MDT) is the daylight saving offset in the Mountain Time Zone, 6 hours behind UTC.

Countries in MDT

United States (Mountain)Canada (Alberta)

Major Cities in MDT

DenverCalgaryEdmontonSalt Lake CityBoise

Key Facts about MDT

•MDT shares the same offset as CST (UTC-06:00).
•Arizona does not switch to MDT, remaining on MST.

Daylight Saving:Yes – switches to MST

Learn more about MDT on Wikipedia

Comparing Time Zones: IST and MDT

IST runs on India Standard Time (IST) at UTC+05:30. MDT runs on Mountain Daylight Time (MDT) at UTC-06:00. That puts IST 11 hours 30 minutes behind MDT — a difference of -11h 30m at the current offsets.

In practice, when it is 9:00 AM in IST it is 9:30 PM in MDT on the previous day. Midnight in IST is 12:30 PM in MDT. Neither zone observes daylight saving time, so the offset between them stays constant all year.

IST to MDT time conversion table

IST (IST)	MDT (MDT)	Day
12:00 AM	12:30 PM	previous day
6:00 AM	6:30 PM	previous day
7:00 AM	7:30 PM	previous day
8:00 AM	8:30 PM	previous day
9:00 AM	9:30 PM	previous day
12:00 PM	12:30 AM	same day
3:00 PM	3:30 AM	same day
5:00 PM	5:30 AM	same day
6:00 PM	6:30 AM	same day
9:00 PM	9:30 AM	same day

Why people convert IST to MDT time

Scheduling a call from IST to MDT: a 10:00 AM start in IST lands at 10:30 PM in MDT the previous day, so you can confirm the slot without doing the arithmetic yourself.
Handling a -11h 30m gap: IST and MDT have no overlap inside a normal 9-to-5 day, so real-time meetings need an early-morning or late-evening slot on one side. 9:00 AM in MDT is 9:30 PM in IST.
Coordinating a IST-based team with MDT contacts: quoting times in the other side's local clock — not your own — removes the single biggest source of missed meetings.

Always state the zone abbreviation, not just the hour. "3:00 PM IST" is unambiguous; "3 PM" across a -11h 30m gap is not.
With a -11h 30m gap there is no shared 9-to-5 window, so alternate the early start: one week IST takes the early slot, the next week MDT does.

About IST (India Standard Time)

India Standard Time (IST) is the time observed throughout India and Sri Lanka. It is based on the 82.5°E meridian, passing through Mirzapur in Uttar Pradesh. India uses a single time zone despite spanning roughly 30° of longitude, which has been debated. IST does not observe daylight saving time. India is the world's most populous country, making IST one of the most-used time zones globally. The IT outsourcing industry and call centers operate primarily on IST, making the EST-to-IST conversion one of the most searched timezone conversions.

About MDT (Mountain Daylight Time)

Mountain Daylight Time (MDT) is observed during summer months in the Mountain Time Zone, except in Arizona which stays on MST year-round. MDT aligns with Central Standard Time (CST) at UTC-06:00.

Best time to call between IST and MDT

With a -11h 30m offset there is no overlap inside a normal 9 AM – 5 PM day. MDT opens at 9:00 AM MDT, which is 9:30 PM in IST, so real-time calls need an early-morning or late-evening slot on one side.

Business hours overlap

IST and MDT have no shared working hours because of the -11h 30m gap. Teams need to alternate early starts or rely on asynchronous handovers.

IST is 11 hours 30 minutes behind MDT (IST UTC+05:30 → MDT UTC-06:00). There is no shared 9-to-5 window, so plan around an early or late slot. Remember to re-check around daylight-saving transitions.

🕐 Daylight Saving Time Info

IST

Does not observe DST

MDT

☀ Currently in DST

Standard: UTC-07:00 · DST: UTC-06:00

Clocks fall back on Sun, Nov 1, 2026

Learn More About Time

Dive deeper into the fascinating world of timekeeping, time zones, and how they shape our global society:

⏳

History of Timekeeping

From sundials to atomic clocks - 5000 years of measuring time

🌍

How Time Zones Work

UTC, offsets, and why zones don't follow straight lines

☀️

Daylight Saving Time

DST dates, which countries observe it, and the ongoing debate

Frequently Asked Questions

What is the time difference between IST and MDT?

IST (IST, UTC+05:30) is 11 hours 30 minutes behind MDT (MDT, UTC-06:00). The gap is currently -11h 30m.

How do I convert IST time to MDT time?

Add -11h 30m to IST local time. For example, 9:00 AM in IST is 9:30 PM in MDT (previous day).

What time is it in MDT right now?

MDT uses MDT at UTC-06:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -11h 30m offset from IST.