Year

Lore & Background

The term 'year' derives from Proto-Germanic *jǣran and Proto-Indo-European *yeh₁r-om, with cognates in German, Old Norse, Greek, and Latin. Latin annus, from PIE *h₂et-no-, yields English words such as annual, annuity, and anniversary. The Greek word for year, ἔτος, is cognate with Latin vetus 'old', from PIE *wetos- 'year'. In some languages, years are counted by referencing seasons, as in 'summers' or 'winters', or harvests, as in Chinese 年, originally a pictograph of a person carrying wheat.

Reader's Guide

The year is a fundamental unit of time, central to calendars, astronomy, and human organization. The term 'year' also applies to orbital periods of other astronomical objects, such as the Martian year of roughly 1.88 Earth years. Calendar eras assign sequential year numbers from an epoch; the Gregorian era uses Anno Domini (AD) or Common Era (CE), with no year zero. The year's significance extends to fiscal, academic, and seasonal cycles, reflecting its role in measuring both astronomical and human time.

Did You Know?

• The word 'year' derives from Proto-Indo-European *yeh₁r-om, meaning 'year, season'.
• A Martian year is roughly 1.88 Earth years.

Mythic Origins and Dynastic Standardization

The story of Chinese measurement begins in legend. The Liji credits the Yellow Emperor with devising the first units, while the Xiao Erya and Kongzi Jiayu trace length standards to the human body itself. The Records of the Grand Historian notes that these body-based measures created inconsistency across regions, prompting Yu the Great to impose a unified length system. Archaeological evidence supports early formalization: rulers bearing decimal units have been recovered from Shang dynasty tombs, confirming that base-10 numeration was already in use by that era. The Zhou dynasty saw the king grant measurement authority to various nobles, which fragmented standards from state to state. It was not until Qin Shi Huang unified China that a single set of measurement units was imposed nationwide. The Han dynasty inherited these Qin standards and recorded them systematically in the Book of Han, establishing a documentary tradition that later dynasties would follow when proclaiming their own official measures and cataloguing their predecessors' systems.

The Market System and Metric Integration

A distinctive feature of Chinese measurement is the coexistence of decimal numerals, in use since the Shang, with several units built on a hexadecimal (base-16) structure. The modern market system (shìzhì) emerged from a deliberate policy of blending tradition with metrication. In 1915, the Beiyang government issued a law adopting the metric system as standard while also codifying a Chinese-style set based on Qing dynasty definitions. The Nationalist government followed in 1929 with the Weights and Measures Act, which made metric the official standard and confined the newer market-use units—defined as rounded fractions of metric values—to private trade, effective 1 January 1930. The People's Republic continued this dual system via a 1959 State Council decree, redefining one catty as exactly 500 grams and splitting it into ten new taels rather than the old sixteen, while exempting Chinese prescription drugs from conversion to avoid dosing errors. A 1984 decree set a 1990 deadline for full metrication, though farmland measures were granted an extension pending further study.

Ancient Units and Their Internal Logic

The traditional Chinese measurement vocabulary spans length, mass, volume, and time, each with its own internal structure. For length, the chi, bu, and li form a hierarchy whose ratios shifted across dynasties: one bu could equal five or six chi, and one li could comprise 300 or 360 bu. Mass units cluster around the jin (catty), with smaller and larger derived units filling the scale. Volume is perhaps the most distinctive: the Book of Han defines the fundamental unit as the yuè, the space occupied by 1,200 grains of proso millet. One hundred yuè make a gě, and ten gě make a shēng (roughly 0.2 liters). Larger dry measures included the dǒu, hú, and shi or dàn. These grain-based volume units also served as salary denominations for imperial bureaucrats, linking measurement directly to governance. By the Qing dynasty, the shēng had converged closely with the modern metric liter. Small units such as lí and fēn appear across length, area, and mass, but their magnitudes differ depending on the quantity they measure.

Regional Divergence in the Modern Era

Today, the legacy of the market system plays out differently across Chinese-speaking territories. On the mainland, the catty is fixed at exactly 500 grams, and the naming convention distinguishes traditional units with the character shì (market) from metric equivalents marked with gōng (common or public) to prevent confusion. Taiwan, having had its traditional units standardized to Japanese values during the colonial period, now uses a metric-based system; its ping, for instance, equals approximately 3.306 square meters, derived from the square ken. The Hong Kong Special Administrative Region retains its traditional units in active legal use, with the catty defined at precisely 604.78982 grams under local statute. A 1976 Metrication Ordinance permitted gradual adoption of SI units, and as of 2012 all three systems—metric, Imperial, and Chinese—remain legal for trade. Macau's 1992 law allowed Chinese, Imperial, and US customary units as secondary to SI for a transitional period. The islands of Kinmen and Matsu, under Republic of China administration, still retain the 1930 market units.