How do I write dates, times, numbers, and measurements using AP Style?

AP Style: Dates, Times, Numbers, and Measurements

AP Style Dates

• Always use Arabic figures, without st, nd, rd or th.
• Capitalize months.
• When a month is used with a specific date, abbreviate only Jan., Feb., Aug.,
• Sept., Oct., Nov. and Dec. (e.g. Oct. 4 was the day of her birthday.)
• When a phrase lists only a month and year, do not separate the month and
• the year with commas. (e.g. February 1980 was his best month.)
• When a phrase refers to a month, day and year, set off the year with
• commas. 20, 1964, was the day they had all been waiting for.)
• (e.g. Aug. 20, 1964, was the day they had all been waiting for.)

AP Style Times

• Use figures except for noon and midnight
• Use a colon to separate hours from minutes (e.g. 2:30 a.m.)
• 4 o’clock is acceptable, but time listings with a.m. or p.m. are preferred

AP Style Numbers

• Spell out the numbers one through nine; for 10 and up, use Arabic numerals.
• For ages and percentages, always use Arabic numerals, even for numbers less than 10
• Spell out numerals that start a sentence; if the result is awkward, recast the sentence:

Twenty-seven detainees were released yesterday. Yesterday, 993 freshmen entered the college.

• The one exception to this rule is in a sentence that begins with a calendar year: 1938 was a turbulent year for Leon.
• Use Roman numerals for wars, monarchs and Popes: World War II, King George VI, Pope John XXIII
• The figures 1, 2, 10, 101, and so on and the corresponding words — one, two, ten, one hundred one, and so on — are called cardinal numbers. The terms 1st, 2nd, 10th, 101st, first, second, tenth, one hundred first and  so on are called ordinal numbers.
• For large numbers: use a hyphen to connect a word ending in y to another word: twenty-one, one hundred forty-three, seventy-six thousand five hundred eighty-seven
• Do not use commas between other separate words that are part of one number: one thousand one hundred fifty-five
• Spell out casual expressions: A thousand times no!
• Proper names: use words or numerals according to an organization’s practice: 3M, Twentieth Century Fund, Big Ten

AP Style Measurements

• Use Arabic numberals for weight and dimensions and spell out the unit of measurement.

The man was 6 feet tall and the dog weighed 17 pounds. 

• Use hyphens when the measurement becomes a compound modifier.

The 6-foot-2-inch man weighed more than the dog.

• Distances are the same as AP Style Numbers

We traveled eight miles to the airport and flew 100 miles to our destination.

AP Style Currency

• Use the dollar symbol and a figure:

They spent $2 on gum and $10 on chocolates.

• Spell out “cents” when used alone:

She spent 95 cents on soda.

• Combining dollars and cents should be written like this: $5.78, $10.05

Sources: eHow.com & The COM Writing Center.