If days and months or days, months, and years are written, use the international date style—that is, day, month, year or day/month/year. If the month is to be abbreviated (consult Editorial Services’ figure styles and tables document), always use the three-letter abbreviation. Do not use a zero before days:
Examples: 3 October 2002, 3/Oct/02, 7 December 1889, meeting on 30 March.
For abbreviations with quarters and years, use the following format:
Example (long-form abbreviation): Q1 2014, Q2 2002.
Example (short-form abbreviation): Q1/14, Q2/02.
Use your discretion for well-known dates.
Examples: 11 September 2001 or September 11 remembrance; 4 July 1776, or July 4 parade, or Fourth of July celebration.
See CMS 10.42 for guidance on formatting times of day.