2.2.4 Inclusive Numbers: Dates

Use all digits in inclusive dates, whether the dates are BCE, CE, or common modern years. Do not shorten the second year in a date range.

correct

506–501 BCE
44 BCE–14 CE
156–159 CE
the years 1914–1918
from 1939 to 1945
between 1967 and 1973
during the 1980s and 1990s

Incorrect

506–1 BCE
156–59 CE
from 1939–45
between 1967–73
during the 1980s and ’90s

When a date range appears in a title, chapter title, or section heading, use all digits unless the cited source itself shortens the dates. In that case, preserve the form used in the original title.

For chronological era abbreviations, see §6.1.2: Historical Eras.