Using specific guidelines for numbers and digits makes scanning for information easier.

Date and Time

  • Use a 12-hour time format and include the 12-hour period and timezone. The timezone should be abbreviated and in all uppercase.

    For example, “The meeting is at 1:00 pm EST.”

  • Use a lowercase acronym after the numeric time.

    For example, “The revisions were made on 01-31-2030.”

  • Use a MM-DD-YYYY format for dates or write the date out in full.

    For example, “The meeting is on January 31, 2030.”


  • Spell out numbers one through nine

    For example: “Select two options.”

  • Use numerals for numbers 10+

    For example, “Select 12 files in the file listing.”

  • Use a comma in numbers of four digits or more

    For example, “There are over 5,000 combinations.”