Babylonian calendar in the context of "Week"

Iraq, officially the Republic of Iraq, is a country in West Asia. Located within the geo-political region of the Middle East, it is bordered by Saudi Arabia to the south, Turkey to the north, Iran to the east, the Persian Gulf and Kuwait to the southeast, Jordan to the southwest, and Syria to the west. The country covers an area of 438,317 square kilometres (169,235 sq mi) and has a population of over 46 million, making it the 58th largest country by area and the 31st most populous in the world. Baghdad, home to over 8 million people, is the capital city and the largest in the country.

Starting in the 6th millennium BC, the fertile plains between Iraq's Tigris and Euphrates rivers, referred to as Mesopotamia, fostered the rise of early cities, civilisations, and empires including Sumer, Akkad, Babylonia, and Assyria. Known as the cradle of civilisation, Mesopotamia saw the invention of writing systems, mathematics, navigation, timekeeping, a calendar, astrology, the wheel, the sailboat, and a law code. After the Muslim conquest of Mesopotamia, Baghdad became the capital of the Abbasid Caliphate and a global cultural and intellectual hub during the Islamic Golden Age, home to institutions such as the House of Wisdom. Following Baghdad's destruction by the Mongols in 1258, Iraq came under successive empires and, from the 16th century until the 20th century, was governed within the Ottoman system as a defined region known administratively as ‘the Iraq Region’. Additionally, Iraq holds religious significance in Christianity, Judaism, Yazidism, and Mandaeism.

The Arabic names of the months of the Gregorian calendar are usually phonetic Arabic pronunciations of the corresponding month names used in European languages. An exception is the Assyrian calendar used in Iraq and the Levant, whose month names are inherited via Classical Arabic from the Babylonian and Aramaic lunisolar calendars and correspond to roughly the same time of year.

Though the lunar Hijri calendar and solar Hijri calendar are prominent in the Middle East, the Gregorian calendar is and has been used in nearly all the countries of the Arab world, in many places long before European occupation. All Arab states use the Gregorian calendar for civil purposes. The names of the Gregorian months as used in Egypt, Sudan, and Yemen are widely regarded as standard across the Arab world, although their Classical Arabic names are often used alongside them. In other Arab countries, some modification or actual changes in naming or pronunciation of months are observed.

The Hindu calendar, also called Panchanga (Sanskrit: पञ्चाङ्ग), is one of various lunisolar calendars that are traditionally used in the Indian subcontinent and Southeast Asia, with further regional variations for social and Hindu religious purposes. They adopt a similar underlying concept for timekeeping based on sidereal year for solar cycle and adjustment of lunar cycles in every three years, but differ in their relative emphasis to moon cycle or the sun cycle and the names of months and when they consider the New Year to start. Of the various regional calendars, the most studied and known Hindu calendars are the Shalivahana Shaka (associated with the King Shalivahana and basis for the Indian national calendar) found in the Deccan region of Southern India and the Vikram Samvat (Bikrami) found in Nepal and the North and Central regions of India – both of which emphasize the lunar cycle. Their new year starts in spring. In regions such as Tamil Nadu and Kerala, the solar cycle is emphasized and this is called the Tamil calendar (though Tamil Calendar uses month names like in Hindu Calendar) and Malayalam calendar and these have origins in the second half of the 1st millennium CE. A Hindu calendar is sometimes referred to as Panchangam (पञ्चाङ्गम्), which is also known as Panjika in Eastern India.

The ancient Hindu calendar conceptual design is also found in the Babylonian calendar, the Chinese calendar, and the Hebrew calendar, but different from the Gregorian calendar. Unlike the Gregorian calendar which adds additional days to the month to adjust for the mismatch between twelve lunar cycles (354 lunar days) and approximately 365 solar days, the Hindu calendar maintains the integrity of the lunar month, but inserts an extra full month, once every 32–33 months, to ensure that the festivals and crop-related rituals fall in the appropriate season.

This is a list of calendars. Included are historical calendars as well as proposed ones. Historical calendars are often grouped into larger categories by cultural sphere or historical period; thus O'Neil (1976) distinguishes the groupings Egyptian calendars (Ancient Egypt), Babylonian calendars (Ancient Mesopotamia), Indian calendars (Hindu and Buddhist traditions of the Indian subcontinent), Chinese calendars and Mesoamerican calendars. These are not specific calendars but series of historical calendars undergoing reforms or regional diversification.

In Classical Antiquity, the Hellenic calendars inspired the Roman calendar, including the solar Julian calendar introduced in 45 BC. Many modern calendar proposals, including the Gregorian calendar introduced in 1582 AD, contains modifications from that of the Julian calendar.

Tishrei (/ˈtɪʃreɪ/; Hebrew: תִּשְׁרֵי‎ [tiʃˈʁej] ) or Tishri (/ˈtɪʃriː/; תִּשְׁרִי‎ [tiʃˈɾi]; from Akkadian tašrītu 'beginning') is the first month of the civil year (which starts on 1 Tishrei) and the seventh month of the ecclesiastical year (which starts on 1 Nisan) in the Hebrew calendar. The name of the month is Babylonian. It is a month of 30 days. Tishrei usually occurs in September–October on the Gregorian calendar.

In the Hebrew Bible the month is called Ethanim (Hebrew: אֵתָנִים – 1 Kings 8:2), or simply the seventh month. In the Babylonian calendar the month is known as Araḫ Tišritum, "Month of Beginning" (of the second half-year).

Akitu or Akitum (Sumerian: 𒀉𒆠𒋾, romanized: a-ki-ti)(Akkadian: 𒀉𒆠𒌈, romanized: akītu(m))is a spring festival and New Year's celebration, held on the first day of the Assyrian and Babylonian Nisan in ancient Mesopotamia and in Assyrian communities around the world, to celebrate the sowing of barley. Akitu originates from the Sumerian spring New Year festival of Zagmuk.

Sivan (Hebrew: סִיוָן, Modern: Sivan, Tiberian: Siwān, from Akkadian simānu, meaning "season; time") is the ninth month of the civil year and the third month of the religious year on the Hebrew calendar. It is a month of 30 days. Sivan usually falls in May–June on the Gregorian calendar.

Along with all other current, post-biblical Jewish month names, Sivan was adopted during the Babylonian captivity. In the Babylonian calendar it was named Araḫ Simanu.

Tevet (Hebrew: טֵבֵת‎, Standard Ṭevet; Tiberian Ṭēḇēṯ; from Akkadian ṭebētu) is the fourth month of the civil year and the tenth month of the ecclesiastical year on the Hebrew calendar. It follows Kislev and precedes Shevat. It is a month of 29 days. Tevet usually occurs in December–January on the Gregorian calendar. In the Babylonian calendar its name was Araḫ Ṭebētum, the "muddy month".