Nowruz

The Solar Hijri calendar, also known as the Iranian or Persian calendar, is a solar calendar used in Iran and Afghanistan. It begins on the day of the vernal equinox, Nowruz, the Persian New Year, according to the Gregorian calendar between March 19 and 21. It counts the years from the Hijra (Arabic, the migration the Prophet Muhammad from Mecca to Medina in 622 CE. According to the Iranian calendar, there are 365 days and twelve months in a year. The first six months have 31 days, followed by five 30 days long months, while the last month has 29. In leap years, a day is added to the last month of the year. This calendar is widely used for both civil and religious purposes in Iran and Afghanistan.

The Islamic calendar, also known as the Hijri Calendar, is a lunar calendar Muslims use to determine the dates of religious holidays. (In many Muslim countries, the Gregorian calendar serves secular time keeping.) The Hijri calendar also begins in 622 CE, marking the migration of the Prophet Muhammad from Mecca to Medina. AH, short for Anno Hegirae in Latin, marks the time of Muslim calendar. The twelve lunar months long year according to the Muslim calendar is 354 or 355 days long.

The Gregorian calendar is the most widely used calendar in the world today. Pope Gregory XIII introduced it in 1582, as a reform of the previously used Julian calendar. While the Catholic Italian and German states, Spain, and Portugal adopted it immediately, Protestant Europe, Japan, China, and Soviet Russia introduced it gradually from the end of the seventeenth century. It is a solar calendar, with a 365 days long year. Every fourth year is a 366 days long leap year.

The Hebrew calendar is a lunisolar calendar. It is built on the lunar cycle and the Earth’s revolving around. The calendar consists of twelve months in a regular year. To synchronize the lunar cycles with the solar year, bi- or tri-annually throughout a nineteen-year period, an additional lunar leap month is added to the year. According to the Hebrew calendar, the day starts in the evening, around sunset. Each month begins on the evening of the day of the new moon and the calendar year begins in the autumn of the northern hemisphere, on the first day of the month Tishrei. The calendar counts time from the creation of the world according to the Hebrew Bible.

The Chinese calendar is also a lunisolar calendar. The year is divided into twelve months, each starting on the day of the new moon, and a leap month is added approximately every two–three years. The Chinese New Year falls on the new moon between January 21 and February 20 according to the Gregorian calendar. Each year is assigned an animal sign based on a twelve-year cycle. The Korean and Vietnamese New Years coincides with the Chinese New Year. In various countries, the Chinese New Year is celebrated, although not as an official holiday.