Commas in dates

In dates, the year is set off from the rest of the sentence with a pair of commas.

Example sentence with editing. Original sentence: On December 12 1890 orders were sent out for the arrest of Sitting Bull. Revised sentence: On December 12, 1890, orders were sent out for the arrest of Sitting Bull.

Commas are not needed if the date is inverted or if only the month and year are given.

Example sentence: The recycling plan went into effect on 15 April 2002.

Example sentence: January 2004 was an extremely cold month.

Exercise: Major uses of the comma 1

Exercise: Major uses of the comma 2

Exercise: All uses of the comma