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).

Colombia to AST

+1h

Colombia

COTSOURCE

UTC-05:00

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

AST

UTC-03:00☀ DST active

HH01

MM00

13:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

Colombia

AST

12:00 AM

2:00 AM

4:00 AM

6:00 AM

8:00 AM

10:00 AM

12:00 PM

2:00 PM

4:00 PM

6:00 PM

8:00 PM

10:00 PM

12:00 AM+1

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

COT and AST on the World Map

The map below highlights the COT (Colombia Time) and AST (Atlantic Standard Time) timezone regions across the globe.

COT Zone

→

AST Zone

Explore all world timezones interactively →

COT – Colombia Time

UTC-05:00

Colombia Time (COT) is the standard time for Colombia, 5 hours behind UTC.

Countries in COT

Colombia

Major Cities in COT

BogotáMedellínCaliBarranquillaCartagena

Key Facts about COT

•Colombia does not observe daylight saving time.
•COT is the same offset as EST (UTC-05:00).
•Bogotá sits at 2,640m elevation, making it one of the highest capital cities.

Daylight Saving:No – UTC-05:00 year-round

Learn more about COT on Wikipedia

AST – Atlantic Standard Time

UTC-04:00

Atlantic Standard Time (AST) is the time zone for the Canadian Atlantic provinces and the Caribbean, 4 hours behind UTC.

Countries in AST

Canada (Atlantic provinces)Puerto RicoUS Virgin IslandsDominican RepublicVenezuelaBoliviaBarbadosTrinidad and Tobago

Major Cities in AST

HalifaxSan JuanSanto DomingoCaracasLa PazFrederictonCharlottetown

Key Facts about AST

•Puerto Rico uses AST year-round and does not observe DST.
•AST is 1 hour ahead of EST.
•Halifax, the capital of Nova Scotia, is the largest city in AST Canada.

Daylight Saving:Yes – switches to ADT

Learn more about AST on Wikipedia

Colombia vs AST: Offsets, DST and Best Call Times

Colombia runs on Colombia Standard Time (COT) at UTC-05:00. AST runs on Atlantic Standard Time (AST) at UTC-04:00. That puts Colombia 1 hour ahead of AST — a difference of +1h at the current offsets.

In practice, when it is 9:00 AM in Colombia it is 10:00 AM in AST. Midnight in Colombia is 1:00 AM in AST. Neither zone observes daylight saving time, so the offset between them stays constant all year.

Colombia to AST time conversion table

Colombia (COT)	AST (AST)	Day
12:00 AM	1:00 AM	same day
6:00 AM	7:00 AM	same day
7:00 AM	8:00 AM	same day
8:00 AM	9:00 AM	same day
9:00 AM	10:00 AM	same day
12:00 PM	1:00 PM	same day
3:00 PM	4:00 PM	same day
5:00 PM	6:00 PM	same day
6:00 PM	7:00 PM	same day
9:00 PM	10:00 PM	same day

Why people convert Colombia to AST time

Scheduling a call from Colombia to AST: a 10:00 AM start in Colombia lands at 11:00 AM in AST, so you can confirm the slot without doing the arithmetic yourself.
Finding shared working hours: both Colombia and AST are inside the 9-to-5 working day between 9:00 AM and 4:00 PM COT time (10:00 AM–5:00 PM AST). That is roughly 7 hours of usable overlap.
Keeping family and friends in sync: knowing that 8:00 PM in Colombia is 9:00 PM in AST makes it easy to avoid calling at 3 AM.

Always state the zone abbreviation, not just the hour. "3:00 PM COT" is unambiguous; "3 PM" across a +1h gap is not.
Block 9:00 AM–4:00 PM COT as the recurring meeting window if you work primarily from Colombia and need AST colleagues present.

About COT (Colombia Time)

Colombia Time (COT) is used throughout Colombia. Colombia does not observe daylight saving time. COT shares the same offset as EST (UTC-05:00). Bogotá, the capital, is one of the largest cities in South America.

About AST (Atlantic Standard Time)

Atlantic Standard Time (AST) covers Canada's Atlantic provinces (Nova Scotia, New Brunswick, Prince Edward Island, and most of Labrador), as well as several Caribbean nations. Puerto Rico and the US Virgin Islands use AST year-round without daylight saving time. The Canadian provinces switch to Atlantic Daylight Time (ADT) in summer.

Best time to call between Colombia and AST

Both Colombia and AST sit inside the 9 AM – 5 PM working day between 9:00 AM–4:00 PM COT, which is 10:00 AM–5:00 PM AST. That gives roughly 7 hours of shared time — the safest window for a live call or meeting.

Business hours overlap

Colombia and AST share 7 hours of working-hours overlap (9:00 AM–4:00 PM COT), so scheduling a live meeting is straightforward.

Colombia is 1 hour ahead of AST (COT UTC-05:00 → AST UTC-04:00). The shared working window is 9:00 AM–4:00 PM COT. Remember to re-check around daylight-saving transitions.

🕐 Daylight Saving Time Info

Colombia

Does not observe DST

AST

☀ Currently in DST

Standard: UTC-04:00 · DST: UTC-03:00

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 Colombia and AST?

Colombia (COT, UTC-05:00) is 1 hour ahead of AST (AST, UTC-04:00). The gap is currently +1h.

How do I convert Colombia time to AST time?

Add +1h to Colombia local time. For example, 9:00 AM in Colombia is 10:00 AM in AST.

What time is it in AST right now?

AST uses AST at UTC-04:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +1h offset from Colombia.

What is the best time to call AST from Colombia?

Call between 9:00 AM and 4:00 PM COT — that maps to 10:00 AM–5:00 PM AST and keeps both parties inside the working day.

Which is ahead, Colombia or AST?

Colombia is 1 hour ahead of AST. When it is 12:00 PM in Colombia it is 1:00 PM in AST.

Do Colombia and AST use different time zones?

Colombia (Colombia) uses COT at UTC-05:00, while AST uses AST at UTC-04:00. The IANA identifiers are America/Bogota and America/Halifax.

Does daylight saving time affect the Colombia–AST difference?

Neither zone observes daylight saving time, so the +1h offset between Colombia and AST is fixed all year.

Which other cities share Colombia's time zone?

COT also covers Bogotá, Medellín, Cali, Barranquilla, Cartagena.

Which countries use COT, Colombia's zone?

COT is used in Colombia.

Is there a day difference between Colombia and AST?

Not normally. The +1h gap only pushes the date over for late-evening times.

What is the time difference between Colombia and AST?

AST is +1h from Colombia.

What timezone is Colombia in?

Colombia operates on its local timezone.

What timezone is AST in?

AST operates on its local timezone.

Which countries use COT (Colombia Time)?

COT is used in Colombia.

Does COT observe daylight saving time?

No, COT does not observe daylight saving time and remains at UTC-05:00 year-round.

What are some interesting facts about COT?

Colombia does not observe daylight saving time. COT is the same offset as EST (UTC-05:00).

Which cities are in the AST timezone?

Major cities in the AST timezone include Halifax, San Juan, Santo Domingo, Caracas, La Paz, Fredericton, Charlottetown.

What is the UTC offset for AST?

Atlantic Standard Time (AST) is at UTC-04:00. During daylight saving time, it shifts to ADT.

What should I know about the AST timezone?

Puerto Rico uses AST year-round and does not observe DST. AST is 1 hour ahead of EST.

When is it midnight in Colombia, what time is it in AST?

When it is 12:00 AM (midnight) in Colombia (COT), it is +1h later in AST (AST).

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Colombia to AST

Colombia

AST

COT and AST on the World Map

COT – Colombia Time

AST – Atlantic Standard Time

Colombia vs AST: Offsets, DST and Best Call Times

Colombia to AST time conversion table

Why people convert Colombia to AST time

About COT (Colombia Time)

About AST (Atlantic Standard Time)

Best time to call between Colombia and AST

Business hours overlap

🕐 Daylight Saving Time Info

Colombia

AST

Learn More About Time

Frequently Asked Questions

What is the time difference between Colombia and AST?

How do I convert Colombia time to AST time?

What time is it in AST right now?

What is the best time to call AST from Colombia?

Which is ahead, Colombia or AST?

Do Colombia and AST use different time zones?

Does daylight saving time affect the Colombia–AST difference?

Which other cities share Colombia's time zone?

Which countries use COT, Colombia's zone?

Is there a day difference between Colombia and AST?

What is the time difference between Colombia and AST?

What timezone is Colombia in?

What timezone is AST in?

Which countries use COT (Colombia Time)?

Does COT observe daylight saving time?

What are some interesting facts about COT?

Which cities are in the AST timezone?

What is the UTC offset for AST?

What should I know about the AST timezone?

When is it midnight in Colombia, what time is it in AST?

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