Dates and times

Write specific dates within the body of a text as follows, abbreviating the month.

  • Saturday, Sept. 19, 1998
  • Wednesday, Nov. 25


Do not change the order of construction, e.g. do not use "Saturday, 19 Sept."

NOTE: The months of March, April, May, June and July are never abbreviated.

When writing approximate dates within the body of a text, spell out the month in full.

  • During December (month only)


Avoid commas when you are referring to a specific month within a specific year.

  • Starting in September 1999 (no comma, month spelled out in full, year listed numerically.)
  • The target for completion of the project is August 1999.


When writing about decades, use numbers, and no apostrophe:

  • The 1920s, the 1980s, the ‘80s, the mid-1960s.

When a decade is used as an adjective:

  • A 1980's computer monitor.

When writing about periods of time over years, write the numbers out in full using a hyphen not a slash.

  • 1985-1990 (not ‘85-‘90)
  • 2000-2001 (not 2000-‘01 or 2000/2001)


When writing about centuries, as with numbers spell out the first nine as words, and use digits for 10 and above.

  • the fifth century
  • the 19th century


Hours are written numerically with no zeros. Use periods with a.m. and p.m. with a space following the number

  • 9 a.m. (not 9:00am) 11 p.m. but 11:45 p.m.
  • noon (not 12 noon. The 12 is redundant.)


A range of times is written using a hyphen.

  • The reception runs from 2-3 p.m.


NOTE: The above rules for dates and times apply within the body of text. In calendars, tables, forms or graphs where space is extremely tight, short forms and figures can be used.