Calendar

A calendar (Latin: calendārium, from calends "first day of the month") is a system of measuring long periods of time. Calendars start from a date called an epoch.

Calendars predate written history, as reflected by astrological monuments such as Newgrange and Stonehenge in the British Isles, Uxmal in Mexico, and the Nebra sky disc in prehistoric Germany.

Julian calendar

The Julian calendar was developed by Julius Caesar and Augustus during classical antiquity. This calendar lasted until the modern era until the gradual adoption of the Gregorian calendar starting in the 16th century. The hesitancy to adopt the reforms was associated with anti-Catholicism.

Gregorian calendar

The Gregorian calendar is the system of timekeeping which predominates globally. Most Islamic countries record dates primarily in Gregorian terms rather than in the Islamic calendar, and East Asian countries in the historic Chinese sphere of influence continue to use the Chinese calendar only for computing religious dates. In Chinese, dates in the Gregorian calendar are referred to only by number: "Month five, weekday six, day thirty-one".

Old Style and New Style dates

In the Orthodox Russian Empire, the Julian calendar was preserved into the 20th century, at least partially because of the religious associations of the Gregorian system. This resulted in a shift of about 12 days between the two calendars, a difference which persisted into the eventful year 1917 and therefore caused certain dates to differ between the western and eastern systems. Thus, the February Revolution occurred in the Gregorian month of March, and the October Revolution of October 25th actually took place on what now would be called November 7th. Shortly after the Bolshevik seizure of power, the RSFSR finally implemented the reform in 1918 by skipping from February 1st to February 13th.

Dates recorded using the Julian calendar are now referred to as Old Style (O.S.) dates, and Gregorian dates are called New Style (N.S.).

Further calendar reform

Several proposals for calendar reform exist. These proliferated during the 20th century, the height of the progressive liberal ideology which predated the nihilistic postmodern era. This coincided with auxiliary language proposals such as Esperanto, spelling and language reforms, timekeeping reforms, secularization, and other proposals which were intended to dissolve national distinctions, end wars, and coordinate the flow of capital. However, many proponents of these ideas were also socialists who saw the incompatibility of the liberal idea of progress with the liberal economic order.