Convert Calendars

Please select a date for the Gregorian, Julian, Jewish, Islamix or Thai calendar to convert them into each other. The curent date is preset as default value.

2.499 The Gregorian calendar is commonly used in the Western world. This calendar, along with the others mentioned - Julian, Jewish, Islamic, and Thai - can be converted to each other, though with varying degrees of complexity.

The Julian calendar was introduced in 46 BCE by order of Julius Caesar. Whereas the year count started retrospectively in the year 525, with the year 1 being the presumed date of Christ's birth. Under this calendar, a normal year had 365 days, with a leap year every four years, consisting of 366 days and February 29th as the leap day. This calendar was based on a year length of 365 1/4 days. However, the actual length of a year is 365.2421875 days, meaning the Julian calendar was about 11 minutes and 14 seconds too long. Therefore, it was replaced in 1582 by the Gregorian calendar, which has the same start date and is still in use today. The Gregorian calendar also has a leap year every four years, but not every 100 years, and then every 400 years. See the list of leap years for details.
The Jewish calendar is a lunisolar calendar, meaning it takes both the moon and the sun into account. The months are determined by the new moon, and a year has 12 months. Since 29.53 days pass between two new moons, a year is about 11 days too short, so an intercalary month is added approximately every three years. The Jewish calendar was established in the year 359, and its counting begins in the year 3761 BCE, the then presumed date of the creation of the world.
The Islamic calendar is a purely lunar calendar, based on the phases of the moon. A year has 12 months of either 29 or 30 days each, making the year approximately 354 or 355 days long, about 11 days shorter than the solar year. Leap years, with an extra day, are inserted after a fixed 30-year cycle, resulting in a total of 11 leap years per cycle. Months begin with the sighting of the new moon, with the first month, Muharram, determining the year's numbering. The Islamic year begins with the Hijra, the migration of the Prophet Muhammad from Mecca to Medina in 622 AD (Julian calendar), which is considered year 1 of the Islamic calendar.
The Thai solar calendar is based on the Gregorian calendar but uses the Buddhist era, which begins 543 BCE with the death and attainment of Nirvana by Buddha Siddhartha Gautama.