Dates and Time


Always spell out names of months when it stands alone, with specific years and when space allows. If necessary, only use abbreviations when used with a specific date.

  • Examples: She graduated in December 2011. She graduated on Dec. 14, 2011.

Always use numerals as dates. Do not add suffixes (th, st, etc.) to numerals unless used for street names.
When using a specific date in running text, use a comma after the year. However, do not use a comma to separate the month and year when there is not a specific date.

  • Examples: She graduated on Dec. 14, 2002, from the University of Colorado Boulder. She graduated in December 2002.

Use four digits when referencing a specific year (2008).

When referencing a range of years, it is acceptable to use a two-digit year (2008-09).

If using numerals for the month, day and year (only recommended for informal documents) the format is as follows: MM/DD/YYYY, MM-DD-YYYY or MM.DD.YYYY.

If the date referenced occurs in the current year, the year is not necessary.


Use figures for time, except for noon and midnight.

Use a colon to separate hours and minutes. Do not add a colon and zeros for on-the-hour times

    • Example: 10 a.m., not 10:00 a.m.

Specify the time of day by using a.m. or p.m. (lower-case letters with periods and no spaces between).

Avoid redundancies such as 10 a.m. in the morning.