In sentences, spell out days of the week: The first class will be on Wednesday.
In a tabular format such as table entries and chart labels, use a three-letter abbreviation without period:
Sun Mon Tue Wed Thu Fri Sat
When a month is used with a specific day, abbreviate only Jan., Feb., Aug., Sept., Oct., Nov. and Dec.
Spell out March, April, May, June and July even when used with a day:
- Jan. 2 was the coldest day of the month.
- July 19 was unseasonably cool.
Spell out all months when used alone or with only a year, and do not offset the year with a comma:
- January 1972 was a cold month.
However, when a phrase contains a month, day and year, abbreviate months as listed above and set off the year with commas before and after:
- January 1972 was a cold month.
- Feb. 14, 1987, was the target date.
Do not use ordinal suffixes with dates. Not: July 12th.
In formal applications such as university invitations, spell out the day of the week and the month, even when a date is included: Tuesday, February 1, 2012.
In a tabular format such as table entries and chart labels, use a three-letter abbreviation without period: Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Years are the only exception to the rule that a numerical figure cannot begin a sentence:
- 2011 was a busy year for ASU.
Indicate decades in numeral form like any other plural: add “s” in lowercase with no apostrophe:
When using the less formal form of a decade with only two digits, use an apostrophe in place of the missing digits:
Note: Microsoft Word and similar programs will interpret this punctuation as a single opening quotation mark, not an apostrophe. To override this, type a second single quotation mark after the first, then delete the first. This is not optional, as the default is incorrect: the ’80s, not: the ‘80s.
Place commas before and after a year when month and day are also included: July 4, 1976, was the nation’s bicentennial.
Show a range of academic years in text with an en dash between the years. Do not use spaces. Different from AP Style, include four digits for the start year, just the final two years for the end year:
- The 2016–17 academic year begins next fall.
Separate a range of dates with an en dash (no spaces before or after the en dash):
- April 16–May 8.
- Monday, April 16–Tuesday, May 8.
Note: To create an en dash: Mac — Option+Minus keys; PC — Ctrl+Alt+Minus keys. See en dash.
Show a span of calendar years with from-to phrasing, not an en dash: She was an adjunct professor from 2006 to 2010. Not: from 2006–10.
See Formatting, Word list.
Numerical treatment of dates
Do not use numerical treatments of dates, e.g., 8/14/16, in headlines or narrative content.
When using a numerical treatment of a date in "terms and conditions," expiration date, "fine print" or internal-use presentations, separate the date, month and year with a forward slash, e.g., 8/14/16. Do not use hyphens, periods, pipes or any other separator.
- Offer expires 8/17/16.
- Not: Offer expires 08/17/2016.
Spring, summer, winter, fall, autumn
Do not capitalize unless the word begins a sentence or is part of a formal name:
- Spring break.
- Summer solstice.
- Fall semester.
- Winter Olympics.
Use figures except for noon.
Noon is 12 p.m. The brown bag seminar will begin at noon.
Avoid using midnight if it would create ambiguity about what day something is taking place, since some users’ understandings may vary. Instead: 11:59 p.m. Thursday or 12:01 a.m. Friday
Morning and afternoon abbreviations are lowercase with periods, not uppercase or small caps: a.m. and p.m. Include a space between the figure and abbreviation.
Not: AM, A.M., am
- 10 a.m., not: 10 a.m. this morning.
- 12 p.m. or noon, not: 12 noon.
Do not use zeros for the top of the hour: 1 p.m. Not: 1:00 p.m. (An exception may be made for formal invitation format.)
For spans of time in text, use to between the numerals, not a hyphen or dash: The program is scheduled for 9 a.m. to noon.
In tabular format, an en dash may be substituted. Just remember: no spaces before or after the en dash! See en dash.
Use morning or afternoon abbreviations when both are required for clarity. ( 6–7 p.m. is a one-hour span; 6 a.m.–7 p.m. is 11 hours.) The field trip is an all-day event, from 6 a.m. to 5:30 p.m.