Common auxiliaries of time. Table 1g
Scope Note
The common auxiliaries of time denote the date, point of time or range of time of a subject represented by a main UDC number. The basis of date indication is the Christian calendar, but non-Christian systems of time reckoning are also allowed for (in "68" and "69"), as well as other time concepts, e.g. seasons and geologic time
Application Note
NOTATION. In calendar notation (see 'DATES' below), the point separates elements of different magnitudes (year-month-day). Otherwise, a point occurs after every third digit, as usual in UDC. Non-hierarchic numbering is introduced by the asterisk, e.g. under "327" for months. Only arabic numerals are used, e.g. MM should be converted to "2000". CITATION ORDER. The time auxiliary is normally cited after the main number, but since quotation marks are biterminal, they readily permit reversal of order or intercalation. E.g. 'Nineteenth-century chamber music' would normally be denoted by 785.7"18", but if a filing order giving higher priority to date is desired then 785"18"7, or even "18"785.7, is possible. Within the auxiliary itself, the time elements are cited in order of decreasing magnitude. DATES. Dates are denoted by citing the ordinary calendar notation in the order year-month-day, enclosed in quotation marks, e.g. "1898.12.11" 11 December 1898 CE. The order of magnitudes (beginning with the greatest and ending with the least) corresponds to the principle of progression from general to special. In the interests of consistency, the year is always expressed as a four-digit number, and the month and day as two-digit numbers. The non-significant places are occupied by zeros, e.g. "0435.08.04" 4 August 435 CE. CHRISTIAN OR COMMON ERA AND PRE-CHRISTIAN ERA. Dates BCE (Before Common era; also known as Before Christ / BC) and CE (Common era; also known as Anno Domini / AD) may be distinguished by prefixing the minus sign to dates BCE, e.g. "-0054" for 54 BCE, (and optionally the plus sign to dates CE, e.g. "+0043" for 43 CE). This method of distinction need only be used when references to both kinds of date are likely to occur. "-" and "+" may be used without dates to denote the pre-Christian and Christian eras. CENTURIES, DECADES. Centuries and decades may be denoted by 2 and 3 digits respectively, e.g. "03" The 300s (loosely, the 4th century). "19" The 1900s (loosely, the 20th century). "192" The 1920s (1920-1929). "200" The 2000s (first decade, i.e. 2000-2009). RANGES OF TIME. Ranges of several centuries, decades or years may be denoted by the initial and final figures, using the slash or oblique stroke, e.g.. "04/14" The 5th to 15th centuries (the Middle Ages). "1815/1830" The period from 1815 to 1830. "625/627" Glacial and post-glacial periods. When one of the limiting dates is undetermined, it is represented by three dots, e.g. 94(100)".../18" World history up to the (end of the) 19th century. 94(100)"19/..." World history from the (beginning of the) 20th century onwards. SMALLER TIME DIVISIONS. If required, the exact hour, minute or second when an event occurred may be denoted, using two-digit notations separated by points, e.g. "1898." 7 December 1898 at 15 hours, 46 minutes, 3 seconds
Broader class
Narrower classes