West Kalimantan in the context of "Riau Islands Province"

The Riau Islands (Indonesian: Kepulauan Riau; Jawi: كڤولاوان رياو) is a province of Indonesia consisting of a group of islands located in the western part of the country. It was established in 2002 after being separated from the neighboring Riau Province. The capital of the province is Tanjung Pinang, while the largest city is Batam. It shares a maritime border with Riau and Jambi to the west, Bangka Belitung Islands to the south, Singapore to the northeast, Malaysia and West Kalimantan to the east, and Vietnam and Cambodia to the north. It comprises a total of 2,408 islands (1,798 having names) scattered between Sumatra, Malay Peninsula, and Borneo including the Riau Archipelago. Situated on one of the world's busiest shipping lanes along the Malacca Strait and the Natuna Sea (South China Sea), the province shares water borders with neighboring countries such as Singapore, Malaysia, and Brunei. The Riau Islands also have relatively large potential mineral resources and energy, as well as marine resources.

The Riau Islands have played a significant role in the maritime history and civilization of the Nusantara region. Between the 7th and 13th centuries, the area was influenced by the powerful Srivijaya Empire, a major maritime kingdom that controlled trade routes along the Malacca Strait. Evidence of Srivijaya's influence in the Riau Islands can be seen from the discovery of the Pasir Panjang Inscription [id] in Karimun Regency, which shows the existence of religious practices through Buddha's footprints, indicating early settlement and the spread of Buddhism long before the arrival of Islam.

Malay (UK: /məˈleɪ/ mə-LAY, US: /ˈmeɪleɪ/ MAY-lay; endonym: Bahasa Melayu, Jawi script: بهاس ملايو) is an Austronesian language spoken primarily by Malays in several islands of Maritime Southeast Asia and the Malay Peninsula on mainland Asia. The language is an official language of Brunei, Malaysia, and Singapore. Indonesian, a standardized variety of Malay, is the official language of Indonesia and one of the working languages of Timor-Leste. Malay is also spoken as a regional language of ethnic Malays in Indonesia, southeast Philippines and the southern part of Thailand. Altogether, it is spoken by 60 million people across Maritime Southeast Asia.

The language is pluricentric and a macrolanguage, i.e., a group of mutually intelligible speech varieties, or dialect continuum, that have no traditional name in common, and which may be considered distinct languages by their speakers. Several varieties of it are standardized as the national language (bahasa kebangsaan or bahasa nasional) of several nation states with various official names: in Malaysia, it is designated as either Bahasa Melayu ("Malay language") or in some instances, Bahasa Malaysia ("Malaysian language"); in Singapore and Brunei, it is called Bahasa Melayu ("Malay language") where it in the latter country refers to a formal standard variety set apart from its own vernacular dialect; in Indonesia, an autonomous normative variety called Bahasa Indonesia ("Indonesian language") is designated the bahasa persatuan/pemersatu ("unifying language" or lingua franca) whereas the term "Malay" (bahasa Melayu) refers to vernacular varieties of Malay indigenous to areas of Central to Southern Sumatra and West Kalimantan as the ethnic languages of Malay in Indonesia.

The Bangka Belitung Islands (Indonesian: Kepulauan Bangka Belitung) is a province of Indonesia. Situated off the southeastern coast of Sumatra, the province comprises two main land masses — the islands of Bangka and Belitung — and numerous smaller islands. Bangka Belitung is bordered by the Bangka Strait to the west, the Natuna Sea to the north, the Java Sea is to the south and the Karimata Strait to the east; the two principal islands are separated by the Gaspar Strait, within which lie lesser islands such as Lepar, Pongok (or Liak) and Mendanau.

The province's capital and largest city is Pangkalpinang. The province shares maritime borders with South Sumatra to the west, Riau Islands to the north, Banten, the Special Capital Region of Jakarta, West Java, and Central Java to the south, and West Kalimantan to the east. Bangka Belitung covers a land area of 16,690.13 km (6,444.10 sq mi) and had a population of 1,455,678 according to the 2020 census; the official estimate as at mid 2024 was 1,531,530 (comprising 786,010 males and 745,520 females).

Malays (Malay: Orang Melayu, Jawi script: اورڠ ملايو‎) are an Austronesian ethnoreligious group native to the Malay Peninsula, eastern Sumatra, coastal Borneo, and the smaller islands that lie between these locations known as Riau Archipelago. These locations are today part of the countries of Malaysia, Indonesia (eastern and southern Sumatra, Bangka Belitung Islands, West Kalimantan, Riau Islands, and the coast of East Kalimantan), the southern part of Thailand (Pattani, Satun, Songkhla, Trang, Yala, and Narathiwat), Singapore, and Brunei Darussalam.

There is considerable linguistic, cultural, artistic and social diversity among the many Malay subgroups, mainly due to hundreds of years of immigration and assimilation of various regional ethnicity and tribes within Maritime Southeast Asia. Historically, the Malay population is descended primarily from the earlier Malayic-speaking Austronesians and Austroasiatic tribes who founded several ancient maritime trading states and kingdoms, notably Brunei, Kedah, Langkasuka, Gangga Negara, Chi Tu, Nakhon Si Thammarat, Pahang, Melayu and Srivijaya.

Kalimantan (Indonesian pronunciation: [kaliˈmantan]) is the Indonesian portion of the island of Borneo. It constitutes 73% of the island's area, and consists of the provinces of Central Kalimantan, East Kalimantan, North Kalimantan, South Kalimantan, and West Kalimantan. The non-Indonesian parts of Borneo are Brunei and East Malaysia. In Indonesia the whole island of Borneo is also called "Kalimantan".

In 2019, President of Indonesia Joko Widodo proposed that Indonesia's capital be moved to Kalimantan. The People's Consultative Assembly approved the Law on State Capital in January 2022. The future capital, Nusantara, is a planned city that will be carved out of East Kalimantan. A government official said construction is expected to be fully complete by 2045, but the unfinished capital officially celebrated Indonesian Independence Day for the first time and it was scheduled to be inaugurated as the capital city on 17 August 2024, but the move did not take place due to delays of construction.

East Kalimantan (Indonesian: Kalimantan Timur) is a province of Indonesia. Its territory comprises the eastern portion of Borneo/Kalimantan. It had a population of about 3.03 million at the 2010 census (within the present boundary), and 3.766 million at the 2020 census; the official estimate as at mid 2024 was 4,092,984. Its capital is the city of Samarinda, the most populous city on the entire island of Borneo.

East Kalimantan has a total area of 127,346.92 square kilometres (49,168.92 sq mi) and is the third least densely populated province in Kalimantan (after North Kalimantan and Central Kalimantan). The majority of the region shares a maritime border to the east with West Sulawesi and Central Sulawesi; its Cape Mangkalihat separates the Makassar Strait from the Celebes Sea. Its former northernmost region was split off on 25 October 2012 and is now the separate province of North Kalimantan; meanwhile it still shares land border to the west with West Kalimantan and Central Kalimantan; to its south, East Kalimantan borders South Kalimantan. The province bordered Sabah, Malaysia before the creation of North Kalimantan, and still has a short border with Sarawak, Malaysia through Mahakam Ulu Regency.

The Republic of Indonesia, a country located in Southeast Asia has three time zones. Western Indonesia Time (Waktu Indonesia Barat, WIB) is seven hours ahead (UTC+07:00) of the Coordinated Universal Time (UTC), used in the islands of Sumatra, Java, and the western half of Kalimantan. Central Indonesia Time (Waktu Indonesia Tengah, WITA) is eight hours ahead (UTC+08:00), used in the eastern half of Kalimantan, as well as all of Bali, the Lesser Sunda Islands, and Sulawesi. Eastern Indonesia Time (Waktu Indonesia Timur, WIT) is nine hours ahead (UTC+09:00), used in the Maluku Islands and Western New Guinea. About 80% of the Indonesian population live in WIB (UTC+07:00).

In 1908, during the Dutch East Indies colonial era, only Java and the Madura Island were initially given time until 1932, when the government utilised UTC+06:30 up to +09:30. In between those changes in 1918, Central Java (UTC+07:20, now defunct) was the basis for time in select locations: for instance, Padang was 7 minutes behind Central Java. The Japanese occupation of the Indies prompted the simplification of time in Indonesia to just UTC+09:00, also known as the Japan Standard Time. The Dutch reoccupied the country following its 1945 independence with UTC+06:00 up to +09:00 established, but it was reverted to the 1932 system after they recognised Indonesia's sovereignty. The current time zone division is a 1988 revision of a 1964 division, with Bali, West Kalimantan, and Central Kalimantan changing sides. Without any significant season changes, the daylight saving time system is not observed anywhere in Indonesia, as is other Southeast Asian countries.