solar year

In writing spans of years, it is important to choose a style that avoids ambiguity. The practice adopted in this dictionary is, in four-figure dates, to specify the last two digits of the second date if it falls within the same century as the first: 1801–08; 1850–51; 1899–1901 . In writing three-figure bc dates, it is advisable to give both dates in full: 159–156 bc, not 159–56 bc unless of course the span referred to consists of 103 years rather than three years. It is also advisable to specify bc or ad in years under 1000 unless the context makes this self-evident