Инструменты Intosoft

Indonesia to AST

-11h

Indonesia

WIBSOURCE
UTC+07:00
HH12
:
MM00
  
12:00 (24-hr)
12 AM6 AM12 PM6 PM12 AM

AST

AST
UTC-03:00☀ DST active
HH01
:
MM00
  
01:00 (24-hr)
12 AM6 AM12 PM6 PM12 AM
Indonesia
AST
12:00 AM
2:00 PM-1
2:00 AM
4:00 PM-1
4:00 AM
6:00 PM-1
6:00 AM
8:00 PM-1
8:00 AM
10:00 PM-1
10:00 AM
12:00 AM
12:00 PM
2:00 AM
2:00 PM
4:00 AM
4:00 PM
6:00 AM
6:00 PM
8:00 AM
8:00 PM
10:00 AM
10:00 PM
12:00 PM

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

WIB and AST on the World Map

The map below highlights the WIB (Western Indonesia Time) and AST (Atlantic Standard Time) timezone regions across the globe.

WIBASTJakartaSurabayaBandungMedanHalifaxSan JuanSanto DomingoCaracas
WIB Zone
→
AST Zone

Explore all world timezones interactively →

WIB – Western Indonesia Time

UTC+07:00

Western Indonesia Time (WIB, UTC+07:00) covers Java, Sumatra and West Kalimantan, including Jakarta.

Countries in WIB
Indonesia (Java, Sumatra, West Kalimantan)
Major Cities in WIB
JakartaSurabayaBandungMedanPalembang
Key Facts about WIB
  • •Indonesia spans three time zones: WIB (UTC+07:00), WITA (UTC+08:00) and WIT (UTC+09:00).
  • •Indonesia has not observed daylight saving time since 1964.
  • •Jakarta is the largest city in Southeast Asia by population.
  • •WIB shares the UTC+07:00 offset with Indochina Time.
Daylight Saving:No – UTC+07:00 year-round
Learn more about WIB 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

Time Conversion Guide: Indonesia to AST

Indonesia runs on Western Indonesia Time (WIB) at UTC+07:00. AST runs on Atlantic Standard Time (AST) at UTC-04:00. That puts Indonesia 11 hours behind AST — a difference of -11h at the current offsets.

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

Indonesia to AST time conversion table

Indonesia (WIB)AST (AST)Day
12:00 AM1:00 PMprevious day
6:00 AM7:00 PMprevious day
7:00 AM8:00 PMprevious day
8:00 AM9:00 PMprevious day
9:00 AM10:00 PMprevious day
12:00 PM1:00 AMsame day
3:00 PM4:00 AMsame day
5:00 PM6:00 AMsame day
6:00 PM7:00 AMsame day
9:00 PM10:00 AMsame day

Why people convert Indonesia to AST time

  • Scheduling a call from Indonesia to AST: a 10:00 AM start in Indonesia lands at 11:00 PM in AST the previous day, so you can confirm the slot without doing the arithmetic yourself.
  • Handling a -11h gap: Indonesia and AST 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 AST is 10:00 PM in Indonesia.
  • Watching a live event or market open: Indonesia viewers need 10:00 PM in AST to catch a 9:00 AM start there, and 11:00 AM if the event is anchored to Indonesia.
  • Always state the zone abbreviation, not just the hour. "3:00 PM WIB" is unambiguous; "3 PM" across a -11h gap is not.
  • With a -11h gap there is no shared 9-to-5 window, so alternate the early start: one week Indonesia takes the early slot, the next week AST does.

About WIB (Western Indonesia Time)

Western Indonesia Time (WIB, Waktu Indonesia Barat) is one of Indonesia's three time zones, fixed at UTC+07:00 all year. It covers Java, Sumatra, West Kalimantan and the provinces around them — home to Jakarta, the country's capital and largest city, plus Surabaya and Bandung. Indonesia does not observe daylight saving time, so WIB never shifts. WIB shares its UTC+07:00 offset with Indochina Time (ICT) and Christmas Island Time, but is a distinct zone covering the western half of the Indonesian archipelago. The country's other zones are WITA (UTC+08:00) in the centre and WIT (UTC+09:00) in the east.

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 Indonesia and AST

With a -11h offset there is no overlap inside a normal 9 AM – 5 PM day. AST opens at 9:00 AM AST, which is 10:00 PM in Indonesia, so real-time calls need an early-morning or late-evening slot on one side.

Business hours overlap

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

Indonesia is 11 hours behind AST (WIB UTC+07:00 → AST UTC-04:00). 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

Indonesia

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 Indonesia and AST?

Indonesia (WIB, UTC+07:00) is 11 hours behind AST (AST, UTC-04:00). The gap is currently -11h.

How do I convert Indonesia time to AST time?

Add -11h to Indonesia local time. For example, 9:00 AM in Indonesia is 10:00 PM in AST (previous day).

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 -11h offset from Indonesia.

What is the best time to call AST from Indonesia?

There is no shared working-hours window because of the -11h gap. The closest option is 1:00 PM in Indonesia, which is 2:00 AM in AST.

Which is behind, Indonesia or AST?

Indonesia is 11 hours behind AST. When it is 12:00 PM in Indonesia it is 1:00 AM in AST.

Do Indonesia and AST use different time zones?

Indonesia (Indonesia) uses WIB at UTC+07:00, while AST uses AST at UTC-04:00. The IANA identifiers are Asia/Jakarta and America/Halifax.

Does daylight saving time affect the Indonesia–AST difference?

Neither zone observes daylight saving time, so the -11h offset between Indonesia and AST is fixed all year.

Which other cities share Indonesia's time zone?

WIB also covers Jakarta, Surabaya, Bandung, Medan, Palembang.

Which countries use WIB, Indonesia's zone?

WIB is used in Indonesia (Java, Sumatra, West Kalimantan).

Is there a day difference between Indonesia and AST?

Not normally. The -11h gap only pushes the date over the previous day.

What is the time difference between Indonesia and AST?

AST is -11h from Indonesia.

What timezone is Indonesia in?

Indonesia operates on its local timezone.

What timezone is AST in?

AST operates on its local timezone.

Which countries use WIB (Western Indonesia Time)?

WIB is used in Indonesia (Java, Sumatra, West Kalimantan).

Does WIB observe daylight saving time?

No, WIB does not observe daylight saving time and remains at UTC+07:00 year-round.

What are some interesting facts about WIB?

Indonesia spans three time zones: WIB (UTC+07:00), WITA (UTC+08:00) and WIT (UTC+09:00). Indonesia has not observed daylight saving time since 1964.

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 Indonesia, what time is it in AST?

When it is 12:00 AM (midnight) in Indonesia (WIB), it is -11h later in AST (AST).

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