Because my kids graduated from school long ago, I no longer know what’s taught in English class—aside from the “cursive writing” controversy. I only know I see a wide variety of grammar and format errors in the manuscripts I edit and proofread.
Many writers incorrectly format numbers, dates, and times, so I thought I’d give you some basic guidelines today.
In the world of publishing, there are two style books that pull a lot of muscle. In the book world, The Chicago Manual of Style is the primary style guide. This book contains over 1000 pages and instructs on how to handle everything from what to italicize to how to properly use punctuation.
For newspapers and periodicals, The Associated Press Style Guide holds sway.
Let’s not forget The Christian Writer’s Manual of Style, used by many Christian publishing houses and periodicals.
I own all three. These aren’t books you need to purchase, but learning the basics will go along way in cutting your editing costs. Look for these books in your library if you want to see what they’re like.
How to Format Numbers
- If you’re writing a book, spell out numbers zero through one hundred. (The Chicago Manual standard)
- If you’re writing for newspapers or periodicals, spell out only single digits. (The Associated Press standard)
- The above two guidelines also apply to currency.
- If a number begins the sentence, always spell it out.
- When expressing percentages, numerals are used. In general text use percent. Fewer than ten percent of writers know these rules. In scientific and statistical works use the symbol %.
How to Format Dates
- With the year alone, use numerals, unless it begins the sentence, and in that case, I’d rewrite the sentence. I was born in 1956.
- If you abbreviate the year, use an apostrophe (not a single quote). The class of ’07 has their ten-year union this year. (The keyboard shortcut for a beginning apostrophe is Alt+0146.)
- With specific dates, use cardinal numbers, even though it may pronounced as an ordinal. December 10, 2016, marked a tragic day in my life. (Note the comma after the year.) December 10 is a sad day for me.
- For decades, either spell out or use numerals as long as the century isn’t in question. I was born in the fifties. Or… I was born in the 1950s. (Note there is no apostrophe between the year and the s.
How to Format Times of Day
- For whole, quarter, and half hours spell out. I boarded the plane at one thirty a.m.
- When using o’clock, always spell out. My appointment is at nine o’clock. (Don’t use a.m. or p.m. with o’clock.)
- When precise time is required use numerals. The Chicago Manual recommends lowercase a.m. (ante meridiem) and p.m. (post meridiem). The train leaves at 5:52 a.m.
- If there is a need for the time zone, list it in parentheses with all caps. The meeting is at one fifteen p.m. (CST).
In most cases these guidelines will serve you well and give your manuscript a more professional look. Like everything, there are exceptions to the rules—let the publisher or editor worry about those.
Don’t let these guidelines get in your way as you write your first draft. Once you enter the final revision stages and prep your book for a professional editor or for submission, then review your manuscript for these items and correct them.