Grammar and Style Guide
- Academic Terminology
- Corporations and Products
- Proofreader’s Marks and Editing Guidelines
- Punctuation
- Semester Terminology
- Spelling and Usage
- Time and Numbers
century
Lowercase, spelling out numbers less than 10: the first century, the 20th century. For proper names, follow the organization’s practice: 20th Century Fox, Twentieth Century Fund, Twentieth Century Limited.
fractions
Use numerals to show fractions.
5 1/2, not “five and one-half”
75 3/4, not “75 and three-fourths”
months
Capitalize the names of months in all uses. When a month is used with a specific date, abbreviate only Jan., Feb., Aug., Sept., Oct., Nov., Dec. Spell out when using alone, or with a year alone.
Fall semester classes will start on Sept. 2, 2013.
December is the busiest month for shopping.
The photo was taken in July 1998.
numbers
Spell out numbers one through nine and any number that begins a sentence.
John took six courses during fall semester.
Seventy people showed up for the seminar.
There are 12 months in the year.
numerals of 1,000 and above
Use commas in the appropriate places, except for temperatures and years.
RIT has more than 15,000 students.
The boiling point of uranium is 3818°C.
She plans to retire in 2015.
percent
One word. Use numerals when referring to percentages, unless the number is the first word of the sentence; then spell out the number. Repeat percent with each individual figure.
There will be a 7 percent increase in tuition this year.
Seventy-five percent of RIT’s students live on campus.
He said 10 percent to 30 percent of the electorate may not vote.
telephone numbers
Use figures. Use hyphens between sections of the number, not periods. Do not use parentheses around the area codes. The form is 212-621-1500. For international numbers use 011 (from the United States), the country code, the city code, and the telephone number: 011-44-20-7535-1515. The form for toll-free numbers is 800-111-1000. If extension numbers are needed, use a comma to separate the main number from the extension: 212-621-1500, ext. 2.
time
Use figures except for noon and midnight. Use a colon to separate hours from minutes:
11 a.m.
1 p.m.
3:30 p.m.
Avoid such redundancies as 10 a.m. this morning, 10 p.m. tonight, or 10 p.m. Monday night. Use 10 a.m. today, 10 p.m. today, or 10 p.m. Monday.
The construction 4 o’clock is acceptable, but time listings with a.m. or p.m. are preferred.
When using a.m. or p.m., always lowercase, with periods.
time sequences
Spell out: 50 hours, 23 minutes, 14 seconds. When using the abbreviated form, as in sports statistics or similar agate use, or subsequent references, the form is 2:30:21.65 [hours, minutes, seconds, tenths, hundredths].