Comma in Dates

When writing a date, a comma is used to separate the day from the month, and the date from the year.

The American Declaration of Independence was ratified on July 4, 1776.

I was born on Sunday, May 12, 1968.

On Tuesday, April 13th at three o’clock, there will be a meeting for all staff.

Please join us on Saturday, June 14th, 2010, for the marriage of Annie and Michael.

Exception:

The application is to be finished by 31 December 2009.

Although inappropriate for use in formal writing, this format does not require any commas.