Commas are used in dates. They are used in between the day and the year.
March 4, 2006 September 22, 1750 June 1, 1991
Commas are also used in between the names of cities and states or cities and countries.
Portland, Oregon Paris, France Minneapolis, Minnesota
When the names of cities and states(or countries) are in the middle of a sentence, a comma goes after the state or country, too.
Bethany stopped in Burlington, Vermont, on her way home.
In an address, a comma is used between the city name and state abbreviation.
Richmond, VA Juneau, AK
Tip: When only a month and year are given, do not separate them with a comma.
August 1999 February 2014 December 1941
