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).

Colombo to Kathmandu

+0h 15m

Colombo

ISTSOURCE

Sri Lanka · UTC+05:30

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Kathmandu

NPT

Nepal · UTC+05:45

HH12

MM15

12:15 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

Colombo

Kathmandu

12:00 AM

12:15 AM

2:00 AM

2:15 AM

4:00 AM

4:15 AM

6:00 AM

6:15 AM

8:00 AM

8:15 AM

10:00 AM

10:15 AM

12:00 PM

12:15 PM

2:00 PM

2:15 PM

4:00 PM

4:15 PM

6:00 PM

6:15 PM

8:00 PM

8:15 PM

10:00 PM

10:15 PM

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

IST and NPT on the World Map

The map below highlights the IST (India Standard Time) and NPT (Nepal Time) timezone regions across the globe.

IST Zone

→

NPT 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

NPT – Nepal Time

UTC+05:45

Nepal Time (NPT, UTC+05:45) is the time zone for Nepal — one of the few offsets in the world set on a 45-minute increment.

Countries in NPT

Nepal

Major Cities in NPT

KathmanduPokharaLalitpurBharatpurBiratnagar

Key Facts about NPT

•Nepal Time is UTC+05:45 — a 45-minute offset, not a whole or half hour.
•The 45-minute offset was adopted in 1986 to match Kathmandu's solar time.
•Nepal does not observe daylight saving time.
•Nepal is 15 minutes ahead of India, despite sharing a long open border.

Daylight Saving:No – UTC+05:45 year-round

Learn more about NPT on Wikipedia

About Colombo

Wikipedia

Colombo operates on Sri Lanka Time (SLST), UTC+5:30. Sharing India's timezone, Colombo is a key South Asian trade and tourism hub.

Population:752,000

Metro:5.6 million

Business Hours:9:00 AM - 5:00 PM IST

Currency:LKR (Rs)

Stock Exchange:CSE (Colombo Stock Exchange)

Key Landmarks

Galle Face GreenGangaramaya TempleColombo Lotus TowerIndependence SquareDutch Hospital

Did You Know?

Sri Lanka Standard Time (SLST) uses UTC+5:30, same offset as India.

Learn more about IST timezone →

About Kathmandu

Wikipedia

Kathmandu operates on Nepal Time (NPT), one of the world's unique UTC+5:45 timezones. This 15-minute offset from India makes Nepal time distinctive for global coordination.

Population:1.4 million

Metro:3.0 million

Business Hours:10:00 AM - 5:00 PM NPT

Currency:NPR (रू)

Stock Exchange:NEPSE (Nepal Stock Exchange)

Key Landmarks

Boudhanath StupaSwayambhunathDurbar SquarePashupatinath TempleGarden of Dreams

Did You Know?

Nepal Time (NPT) is one of only three timezones offset by 45 minutes (UTC+5:45).

Learn more about NPT timezone →

Colombo vs Kathmandu: Offsets, DST and Best Call Times

Colombo runs on India Standard Time (IST) at UTC+05:30. Kathmandu runs on Nepal Time (NPT) at UTC+05:45. That puts Colombo 15 minutes ahead of Kathmandu — a difference of +0h 15m at the current offsets.

In practice, when it is 9:00 AM in Colombo it is 9:15 AM in Kathmandu. Midnight in Colombo is 12:15 AM in Kathmandu. Neither zone observes daylight saving time, so the offset between them stays constant all year.

Colombo to Kathmandu time conversion table

Colombo (IST)	Kathmandu (NPT)	Day
12:00 AM	12:15 AM	same day
6:00 AM	6:15 AM	same day
7:00 AM	7:15 AM	same day
8:00 AM	8:15 AM	same day
9:00 AM	9:15 AM	same day
12:00 PM	12:15 PM	same day
3:00 PM	3:15 PM	same day
5:00 PM	5:15 PM	same day
6:00 PM	6:15 PM	same day
9:00 PM	9:15 PM	same day

Why people convert Colombo to Kathmandu time

Scheduling a call from Colombo to Kathmandu: a 10:00 AM start in Colombo lands at 10:15 AM in Kathmandu, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both Colombo and Kathmandu are inside the 9-to-5 working day between 9:00 AM and 4:45 PM IST time (9:15 AM–5:00 PM NPT). That is roughly 7 hours 45 minutes of usable overlap.
Keeping family and friends in sync: knowing that 8:00 PM in Colombo is 8:15 PM in Kathmandu makes it easy to avoid calling at 3 AM.

Always state the zone abbreviation, not just the hour. "3:00 PM IST" is unambiguous; "3 PM" across a +0h 15m gap is not.
Block 9:00 AM–4:45 PM IST as the recurring meeting window if you work primarily from Colombo and need Kathmandu colleagues present.

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 NPT (Nepal Time)

Nepal Time (NPT) runs at UTC+05:45, one of only a handful of time zones worldwide that are not a whole or half hour from UTC. Nepal set its offset to 5 hours 45 minutes ahead of UTC in 1986 to mark the country's position between the 75°E and 90°E meridians; Kathmandu's solar time sits just over 5 hours 41 minutes ahead of Greenwich, so the 45-minute offset tracks the sun more closely than either 5:30 or 6:00 would. Nepal does not observe daylight saving time, so NPT is fixed all year. The offset makes Nepal 15 minutes ahead of India Standard Time (UTC+05:30) and 2 hours 15 minutes ahead of Dubai (UTC+04:00).

Best time to call between Colombo and Kathmandu

Both Colombo and Kathmandu sit inside the 9 AM – 5 PM working day between 9:00 AM–4:45 PM IST, which is 9:15 AM–5:00 PM NPT. That gives roughly 7 hours and 45 minutes of shared time — the safest window for a live call or meeting.

Business hours overlap

Colombo and Kathmandu share 7 hours of working-hours overlap (9:00 AM–4:45 PM IST), so scheduling a live meeting is straightforward.

Colombo is 15 minutes ahead of Kathmandu (IST UTC+05:30 → NPT UTC+05:45). The shared working window is 9:00 AM–4:45 PM IST. Remember to re-check around daylight-saving transitions.

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 Colombo and Kathmandu?

Colombo (IST, UTC+05:30) is 15 minutes ahead of Kathmandu (NPT, UTC+05:45). The gap is currently +0h 15m.

How do I convert Colombo time to Kathmandu time?

Add +0h 15m to Colombo local time. For example, 9:00 AM in Colombo is 9:15 AM in Kathmandu.

What time is it in Kathmandu right now?

Kathmandu uses NPT at UTC+05:45. Use the live converter at the top of this page — it updates in real time and already accounts for the +0h 15m offset from Colombo.

What is the best time to call Kathmandu from Colombo?

Call between 9:00 AM and 4:45 PM IST — that maps to 9:15 AM–5:00 PM NPT and keeps both parties inside the working day.

Which is ahead, Colombo or Kathmandu?

Colombo is 15 minutes ahead of Kathmandu. When it is 12:00 PM in Colombo it is 12:15 PM in Kathmandu.

Do Colombo and Kathmandu use different time zones?

Colombo (Sri Lanka) uses IST at UTC+05:30, while Kathmandu (Nepal) uses NPT at UTC+05:45. The IANA identifiers are Asia/Colombo and Asia/Kathmandu.

Does daylight saving time affect the Colombo–Kathmandu difference?

Neither zone observes daylight saving time, so the +0h 15m offset between Colombo and Kathmandu is fixed all year.

Which other cities share Colombo's time zone?

IST also covers Mumbai, Delhi, Bangalore, Kolkata, Chennai, Hyderabad, Pune, Ahmedabad and 4 more.

Which countries use IST, Colombo's zone?

IST is used in India, Sri Lanka.

Is there a day difference between Colombo and Kathmandu?

Not normally. The +0h 15m gap only pushes the date over for late-evening times.

What is the time difference between Colombo and Kathmandu?

Kathmandu is +0h 15m from Colombo.

What timezone is Colombo in?

Colombo operates on Sri Lanka Time (SLST), UTC+5:30. Sharing India's timezone, Colombo is a key South Asian trade and tourism hub.

What timezone is Kathmandu in?

Kathmandu operates on Nepal Time (NPT), one of the world's unique UTC+5:45 timezones. This 15-minute offset from India makes Nepal time distinctive for global coordination.

What are the business hours in Colombo?

Standard business hours in Colombo are 9:00 AM - 5:00 PM IST.

What are the business hours in Kathmandu?

Standard business hours in Kathmandu are 10:00 AM - 5:00 PM NPT.

What is the best time to schedule a call between Colombo and Kathmandu?

The best overlap for a call is when both cities are in business hours. Colombo works 9:00 AM - 5:00 PM IST and Kathmandu works 10:00 AM - 5:00 PM NPT (+0h 15m difference). Try scheduling during the overlapping window for maximum convenience.

What currencies are used in Colombo and Kathmandu?

Colombo uses LKR (Rs) while Kathmandu uses NPR (रू). Check current exchange rates when planning travel or business between these cities.

How do Colombo and Kathmandu compare in size?

Colombo has a population of approximately 752,000 (metro: 5.6 million), while Kathmandu has approximately 1.4 million (metro: 3.0 million).

What are the major landmarks in Colombo and Kathmandu?

Colombo is known for Galle Face Green, Gangaramaya Temple, Colombo Lotus Tower. Kathmandu is famous for Boudhanath Stupa, Swayambhunath, Durbar Square.

Do Colombo and Kathmandu have stock exchanges?

Yes. Colombo has the CSE (Colombo Stock Exchange) and Kathmandu has the NEPSE (Nepal Stock Exchange). The +0h 15m time difference affects trading hour overlaps between these exchanges.