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).

COT to AEST

+15h

COT

COTSOURCE

UTC-05:00

HH12

MM00

12:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

AEST

UTC+10:00DST observed

HH03

MM00

(next day)03:00 (24-hr)

12 AM6 AM12 PM6 PM12 AM

Quick Reference

Time Conversion Table

COT

AEST

12:00 AM

3:00 PM

2:00 AM

5:00 PM

4:00 AM

7:00 PM

6:00 AM

9:00 PM

8:00 AM

11:00 PM

10:00 AM

1:00 AM+1

12:00 PM

3:00 AM+1

2:00 PM

5:00 AM+1

4:00 PM

7:00 AM+1

6:00 PM

9:00 AM+1

8:00 PM

11:00 AM+1

10:00 PM

1:00 PM+1

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

COT and AEST on the World Map

The map below highlights the COT (Colombia Time) and AEST (Australian Eastern Standard Time) timezone regions across the globe.

COT Zone

→

AEST 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

AEST – Australian Eastern Standard Time

UTC+10:00

Australian Eastern Standard Time (AEST) covers eastern Australia, 10 hours ahead of UTC.

Countries in AEST

Australia (NSW, VIC, QLD, TAS, ACT)Papua New Guinea

Major Cities in AEST

SydneyMelbourneBrisbaneCanberraHobartGold Coast

Key Facts about AEST

•Queensland does not observe daylight saving time, staying on AEST year-round.
•Sydney and Melbourne switch to AEDT (UTC+11:00) in summer.
•The Australian Securities Exchange (ASX) operates on AEST/AEDT.
•AEST is 15 hours ahead of EST during winter.

Daylight Saving:Yes – switches to AEDT

Learn more about AEST on Wikipedia

Comparing Time Zones: COT and AEST

COT runs on Colombia Time (COT) at UTC-05:00. AEST runs on Australian Eastern Standard Time (AEST) at UTC+10:00. That puts COT 15 hours ahead of AEST — a difference of +15h at the current offsets.

In practice, when it is 9:00 AM in COT it is 12:00 AM in AEST on the next day. Midnight in COT is 3:00 PM in AEST. Neither zone observes daylight saving time, so the offset between them stays constant all year.

COT to AEST time conversion table

COT (COT)	AEST (AEST)	Day
12:00 AM	3:00 PM	same day
6:00 AM	9:00 PM	same day
7:00 AM	10:00 PM	same day
8:00 AM	11:00 PM	same day
9:00 AM	12:00 AM	next day
12:00 PM	3:00 AM	next day
3:00 PM	6:00 AM	next day
5:00 PM	8:00 AM	next day
6:00 PM	9:00 AM	next day
9:00 PM	12:00 PM	next day

Why people convert COT to AEST time

Scheduling a call from COT to AEST: a 10:00 AM start in COT lands at 1:00 AM in AEST the next day, so you can confirm the slot without doing the arithmetic yourself.
Handling a +15h gap: COT and AEST 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 AEST is 12:00 AM in COT.
Keeping family and friends in sync: knowing that 8:00 PM in COT is 11:00 AM in AEST 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 +15h gap is not.
With a +15h gap there is no shared 9-to-5 window, so alternate the early start: one week COT takes the early slot, the next week AEST does.

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 AEST (Australian Eastern Standard Time)

Australian Eastern Standard Time (AEST) is used in the eastern states of Australia including New South Wales, Victoria, Queensland, Tasmania, and the ACT. During summer (October to April), NSW, VIC, TAS, and ACT switch to Australian Eastern Daylight Time (AEDT, UTC+11:00), while Queensland remains on AEST year-round.

Best time to call between COT and AEST

With a +15h offset there is no overlap inside a normal 9 AM – 5 PM day. AEST opens at 9:00 AM AEST, which is 12:00 AM in COT, so real-time calls need an early-morning or late-evening slot on one side.

Business hours overlap

COT and AEST have no shared working hours because of the +15h gap. Teams need to alternate early starts or rely on asynchronous handovers.

COT is 15 hours ahead of AEST (COT UTC-05:00 → AEST UTC+10:00). 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

COT

Does not observe DST

AEST

❄ Currently in Standard Time

Standard: UTC+10:00 · DST: UTC+11:00

Clocks spring forward on Sat, Oct 3, 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 COT and AEST?

COT (COT, UTC-05:00) is 15 hours ahead of AEST (AEST, UTC+10:00). The gap is currently +15h.

How do I convert COT time to AEST time?

Add +15h to COT local time. For example, 9:00 AM in COT is 12:00 AM in AEST (next day).

What time is it in AEST right now?

AEST uses AEST at UTC+10:00. Use the live converter at the top of this page — it updates in real time and already accounts for the +15h offset from COT.