ACST to COT
-14h 30mACST
ACSTSOURCECOT
COTGreen rows indicate typical business hours (9 AM - 5 PM)
ACST and COT on the World Map
The map below highlights the ACST (Australian Central Standard Time) and COT (Colombia Time) timezone regions across the globe.
ACST – Australian Central Standard Time
UTC+09:30Australian Central Standard Time (ACST, UTC+09:30) covers South Australia and the Northern Territory, on a half-hour offset.
- •ACST uses a half-hour offset: UTC+09:30.
- •South Australia moves to ACDT (UTC+10:30) in summer; the Northern Territory does not.
- •Adelaide and Darwin are 30 minutes apart during daylight saving, level in winter.
- •Adelaide is one of the few major cities on a 30-minute offset.
COT – Colombia Time
UTC-05:00Colombia Time (COT) is the standard time for Colombia, 5 hours behind UTC.
- •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.
ACST to COT Time Difference – Complete Guide
ACST runs on Australian Central Standard Time (ACST) at UTC+09:30. COT runs on Colombia Time (COT) at UTC-05:00. That puts ACST 14 hours 30 minutes behind COT — a difference of -14h 30m at the current offsets.
In practice, when it is 9:00 AM in ACST it is 6:30 PM in COT on the previous day. Midnight in ACST is 9:30 AM in COT. Neither zone observes daylight saving time, so the offset between them stays constant all year.
ACST to COT time conversion table
| ACST (ACST) | COT (COT) | Day |
|---|---|---|
| 12:00 AM | 9:30 AM | previous day |
| 6:00 AM | 3:30 PM | previous day |
| 7:00 AM | 4:30 PM | previous day |
| 8:00 AM | 5:30 PM | previous day |
| 9:00 AM | 6:30 PM | previous day |
| 12:00 PM | 9:30 PM | previous day |
| 3:00 PM | 12:30 AM | same day |
| 5:00 PM | 2:30 AM | same day |
| 6:00 PM | 3:30 AM | same day |
| 9:00 PM | 6:30 AM | same day |
Why people convert ACST to COT time
- Scheduling a call from ACST to COT: a 10:00 AM start in ACST lands at 7:30 PM in COT the previous day, so you can confirm the slot without doing the arithmetic yourself.
- Handling a -14h 30m gap: ACST and COT 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 COT is 6:30 PM in ACST.
- Watching a live event or market open: ACST viewers need 6:30 PM in COT to catch a 9:00 AM start there, and 2:30 PM if the event is anchored to ACST.
- Always state the zone abbreviation, not just the hour. "3:00 PM ACST" is unambiguous; "3 PM" across a -14h 30m gap is not.
- With a -14h 30m gap there is no shared 9-to-5 window, so alternate the early start: one week ACST takes the early slot, the next week COT does.
About ACST (Australian Central Standard Time)
Australian Central Standard Time (ACST) is the half-hour offset of UTC+09:30 used across South Australia and the Northern Territory, taking in Adelaide and Darwin. South Australia moves to Australian Central Daylight Time (ACDT, UTC+10:30) from the first Sunday in October to the first Sunday in April, but the Northern Territory does not observe daylight saving — so Adelaide and Darwin sit 30 minutes apart in summer and level with each other in winter. The half-hour offset means Adelaide is 30 minutes behind Sydney in winter and level with it during daylight saving, which regularly catches out travellers and meeting planners.
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.
Best time to call between ACST and COT
With a -14h 30m offset there is no overlap inside a normal 9 AM – 5 PM day. COT opens at 9:00 AM COT, which is 6:30 PM in ACST, so real-time calls need an early-morning or late-evening slot on one side.
Business hours overlap
ACST and COT have no shared working hours because of the -14h 30m gap. Teams need to alternate early starts or rely on asynchronous handovers.
ACST is 14 hours 30 minutes behind COT (ACST UTC+09:30 → COT UTC-05:00). 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
ACST
❄ Currently in Standard Time
Standard: UTC+09:30 · DST: UTC+10:30
Clocks spring forward on Sat, Oct 3, 2026
COT
Does not observe DST
Learn More About Time
Dive deeper into the fascinating world of timekeeping, time zones, and how they shape our global society:
Frequently Asked Questions
What is the time difference between ACST and COT?
ACST (ACST, UTC+09:30) is 14 hours 30 minutes behind COT (COT, UTC-05:00). The gap is currently -14h 30m.
How do I convert ACST time to COT time?
Add -14h 30m to ACST local time. For example, 9:00 AM in ACST is 6:30 PM in COT (previous day).
What time is it in COT right now?
COT uses COT at UTC-05:00. Use the live converter at the top of this page — it updates in real time and already accounts for the -14h 30m offset from ACST.
What is the best time to call COT from ACST?
There is no shared working-hours window because of the -14h 30m gap. The closest option is 1:00 PM in ACST, which is 10:30 PM in COT.
Which is behind, ACST or COT?
ACST is 14 hours 30 minutes behind COT. When it is 12:00 PM in ACST it is 9:30 PM in COT.
Does daylight saving time affect the ACST–COT difference?
Neither zone observes daylight saving time, so the -14h 30m offset between ACST and COT is fixed all year.
Which other cities share ACST's time zone?
ACST also covers Adelaide, Darwin, Alice Springs, Mount Gambier.
Which countries use ACST, ACST's zone?
ACST is used in Australia (South Australia, Northern Territory).
Is there a day difference between ACST and COT?
Sometimes. The -14h 30m gap is large enough that 8:00 PM or later in ACST already falls on the in COT.
What is the time difference between ACST and COT?
COT is -14h 30m from ACST.
What timezone is ACST in?
ACST operates on its local timezone.
What timezone is COT in?
COT operates on its local timezone.
Which countries use ACST (Australian Central Standard Time)?
ACST is used in Australia (South Australia, Northern Territory).
Does ACST observe daylight saving time?
Yes, ACST switches to ACDT during summer months.
What are some interesting facts about ACST?
ACST uses a half-hour offset: UTC+09:30. South Australia moves to ACDT (UTC+10:30) in summer; the Northern Territory does not.
Which cities are in the COT timezone?
Major cities in the COT timezone include Bogotá, Medellín, Cali, Barranquilla, Cartagena.
What is the UTC offset for COT?
Colombia Time (COT) is at UTC-05:00.
What should I know about the COT timezone?
Colombia does not observe daylight saving time. COT is the same offset as EST (UTC-05:00).
When is it midnight in ACST, what time is it in COT?
When it is 12:00 AM (midnight) in ACST (ACST), it is -14h 30m later in COT (COT).
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See every conversion from ACST →·See every conversion from COT →