The division of time in Indonesia is divided into 3. However, before getting there we must first know how the process is. This article will discuss how time is divided in Indonesia. It will also discuss the history of time division in Indonesia.
How is the division of time in Indonesia?
In one day, the sun will rotate for 23 hours 56 minutes. As we know, the sun will rotate on its axis. The 23 hours 56 minutes is then rounded up to 24 hours.
That rotation will cause the sun to be different in the position of the celestial sphere. The sun will form a complete circle. One complete circle equals 360 degrees.
The circle will be traveled for 24 hours by the sun. If you look at the time for 1 hour, it is equal to 15 degrees. Then, each length of longitude is 15 degrees.
It is then assigned a separate time zone. The time zone is determined by the formula GMT + time in that area. To find out how time is divided in Indonesia, you need to look at its astronomical location.
Based on its astronomical location, the territory of Indonesia is located between coordinates 95 degrees to 141 degrees east longitude. Indonesia is located at 6 degrees north latitude to 11 degrees south latitude. Looking at the location of longitude, the length of Indonesia’s longitude is 46 degrees.
In one hour, the sun rotates on its axis by 15 degrees. Therefore, the territory of Indonesia as seen from the tip or Sabang to the east or Merauke has a time difference of about 3 hours. In addition, because Indonesia is to the east of the city of Greenwich.
This means that the sun will rise first. Therefore, the territory of Indonesia will be earlier than the city of Greenwich. Longitude is one of the factors that becomes the reason for calculating the time division in Indonesia.
For the easternmost country of Indonesia, the time calculation will be based on 135 degrees longitude. That makes the time difference about 9 hours earlier than the city of Greenwich. In the central part of Indonesia, the time calculation will be based on 120 degrees longitude.
Central Indonesia has a time difference of about 8 hours earlier than the city of Greenwich. For western Indonesia, the time calculation will be based on 105 degrees longitude. This makes western Indonesia have a time difference of about 7 hours earlier than the city of Greenwich.
In addition to its astronomical location, the influence of time division is also due to climatic conditions. Given that the country of Indonesia is at a latitude of 23.5 degrees North Latitude and South Latitude. Therefore, the territory of Indonesia is influenced by a tropical climate.
The tropical climate in the territory of Indonesia certainly has consequences or consequences. One of them is on the reception of sunlight throughout the year. Indonesia will receive sunlight with a relatively maximum heat intensity.
Therefore, in dividing the time, the Indonesian state is divided into 3 periods. These times are WIT, WITA and WIB. Here is the explanation:
1. WIT (East Indonesia Time)
The time in eastern Indonesia is called WIT (eastern Indonesia time). The time zone in this region extends along the east longitude of about 135 degrees. This stretch of longitude covers some of the easternmost parts of Indonesia.
The area includes the islands of Maluku and Papua. The time zone for this eastern part of Indonesia can be determined through a formula. The formula is UTC + 9 or GMT + 9.
The provinces on the islands of Maluku and Papua which follow eastern Indonesian time are as follows:
a. Maluku Island
- North Maluku
- West Papua
2. WITA (Central Indonesian Time)
The time in the central part of Indonesia is called WITA. The region’s time zone extends along the east longitude of 120 degrees. The time division in central Indonesia is the same as the international time division.
The time zone for this central part of Indonesia can be determined through a formula. The formula is UTC + 8 or GMT + 8. The stretch of longitude in this region includes several areas in Indonesia.
The area is the entire island of Bali, Nusa Tenggara, Sulawesi and Kalimantan Island. Provinces included in Central Indonesian Time are as follows:
a. Kalimantan island
- North Kalimantan
- East Kalimantan
- South Kalimantan
b. Bali Island
- East Nusa Tenggara
- West Nusa Tenggara
c. Sulawesi island
- West Sulawesi
- Central Sulawesi
- South Sulawesi
- North Sulawesi
3. WIB (Western Indonesian Time)
The time in western Indonesia is called WIB. The time zone of this western region extends along the east longitude of 105 degrees. The time zone for the western part of Indonesia can be determined through a formula.
The formula is UTC + 7 or GMT + 7. The stretch of longitude in this region includes several areas in Indonesia. Like all areas on the islands of Java, Madura, Sumatra and Kalimantan (west and center). Provinces included in western Indonesian time are as follows:
a. Sumatera island
- North Sumatra
- West Sumatra
- South Sumatra
- Riau Archipelago (Kepri)
- Bangka Belitung
b. Java Island
- East Java
- Central Java
- West Java
- In Yogyakarta
- DKI Jakarta
c. Kalimantan island
- West Kalimantan
- Central Kalimantan
History of Time Division in Indonesia
The Governments Besluit rules came into force on May 1, 1908. At that time, the Central Java region was designated as a zodiac or time zone. Central Java Region with GMT + 7:12.
Then a change occurred in 1918, in February to be precise. At that time, the Dutch determined that the Padang region had a time difference from Central Java. The Netherlands set the Padang area less than 39 minutes from the time in the Central Java region.
The Netherlands also decided the time in the Balikpapan area. In the city of Balikpapan, the time is earlier than GMT, which is + 8:20. It didn’t end there, the rules regarding this time were again changed.
The change occurred in 1924. The time change was made by Hoofden van Gewestelijk Bestuur in de Buitengewesten. He is a regional ruler.
In this change, it is determined that the time in the Central Java region has changed. It changes to GMT+7:20. Meanwhile, the Bali and Lombok Residency areas are around + 22 minutes from the time in the Central Java region.
The time in the Makassar region also has +38 minutes from the time in the Central Java region. Meanwhile, the time in the Tapanuli area is less than 45 minutes from the time in the Central Java region. The time in the Padang area is also set at 7 minutes less than the time in the Central Java region.
The Netherlands then again changed the time zone in Indonesia. Changes occurred in 1932. The Dutch divided Indonesia’s time into 6 regions. The six regions have a time difference of about 30 minutes.
For the sake of the military interests of the Japanese government, the time in Indonesia was changed again. This happened in 1942. The changes made were adjusted to the time in Tokyo. It is known that the time in Tokyo is GMT + 9. Therefore, the time zone in the Java region is advanced to GMT + 7:30 or 1:30.
Since the Dutch state came to power again in Indonesia, the time zone has been changed again. Changes occur for reasons of military operations. The change was made on December 10, 1947.
At that time, the time zone in Indonesia was divided into 3 time zones. Those times are +7 at 105 degrees longitude, +8 at 120 degrees longitude, and +9 at 135 degrees longitude. It doesn’t end there, the time zone is changed again.
Changes occur at the time of transfer of sovereignty. This change was made by the Indonesian government. At that time, the time zone in Indonesia was officially divided into 6 time zones.
This division is based on the governor general’s decision. This decision occurred in 1932. When the Dutch succeeded in recapturing Irian Jaya, the Indonesian government again changed its time division.
In 1963, the Indonesian government formalized the Decree of the President of the Republic of Indonesia No. 243 of 1963. The core content of the decision was that the president again divided the territory of Indonesia into three times.
The last change regarding the time zone occurred after the Presidential Decree or Presidential Decree No. 41 of 1987 came into effect. The core content of the presidential decree is that the territory of Indonesia is divided into 3 time zones.
The three time zones are WIT (East Indonesia Time), WITA (Central Indonesia Time) and WIB (Western Indonesia Time).
The State of Indonesia also sets time based on GMT or Green Mean Time. Based on the GMT rules, the time zone in Indonesia is divided into 3 parts. This decision is in effect to date.
That is an explanation of the division of time in Indonesia. Find other interesting information at www.sinaumedia.com . sinaumedia as #FriendsWithoutLimits always presents interesting articles and recommendations for the best books for Sinaumed’s,
Author: Wida Kurniasih
Source: from various sources
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