Places, Dates, Titles

31. When Do I Use Commas?

D. In places, titles, and dates

I. Commas are used to separate clarifying information in the proper names of geographic places, proper titles, and certain forms of date. The rules governing this are similar to those for non-essential and parenthetical comma use—the comma is used to separate part of the information that clarifies the main point, but is not necessarily important in its own right.

• Example: “Dr. Mark Damen, Ph.D., teaches Ancient Near Eastern history at USU.”

The “Ph.D.” is not necessary in this statement, but it is part of the subject's official title and so is included and separated by commas.

• Example: “We took a vacation to Colorado Springs, Colorado, earlier this year.”

The state, “Colorado,” is not required in this sentence, but it clarifies the subject (Colorado Springs) and so is included for that purpose. Because it is parenthetical to the subject, however, it requires a preceding and concluding comma.

• Example: “Caesar was betrayed and murdered on March 15, 44 BC, in the theater of Pompey.”

“44 BC” is the clarifying part of the date, and so requires enclosure in commas.

Note: commas are not needed in the date form day month year, i.e. “6 April 1893.” This is a common construction in historical writing specifically.

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I.	Commas are used to separate clarifying information in the proper names of geographic places, proper titles, and certain forms of date. The rules governing this are similar to those for non-essential and parenthetical comma use—the comma is used to separate part of the information that clarifies the main point, but is not necessarily important in its own right.

	• Example: “Dr. Mark Damen, Ph.D., teaches Ancient Near Eastern history at USU.”
	The “Ph.D.” is not necessary in this statement, but it is part of the subject's official title and so is included and separated by commas.

	• Example: “We took a vacation to Colorado Springs, Colorado, earlier this year.”
	The state, “Colorado,” is not required in this sentence, but it clarifies the subject (Colorado Springs) and so is included for that purpose. Because it is parenthetical to the subject, however, it requires a preceding and concluding comma.

	• Example: “Caesar was betrayed and murdered on March 15, 44 BC, in the theater of Pompey.”
	“44 BC” is the clarifying part of the date, and so requires enclosure in commas.
	Note: commas are not needed in the date form day month year, i.e. “6 April 1893.” This is a common construction in historical writing specifically.