The idea of learning and understanding the many grammar rules in the English language can be daunting. There are many different uses of punctuation within sentences, and recognizing the difference between when to use them is important for written English. One common area for questions is when to use commas, including how commas are to be used in regards to a date in a sentence.

Commas and Written Dates

It is appropriate to use a comma when you are separating the day of the month from the year in a written sentence. A second comma is placed after the year in the sentence. The rest of the sentence comes after the second comma.


1) We are having the party on Oct. 4, 2011, in our backyard.

2) Her classes will begin Aug. 22, 2012, at the local community college.

Commas with Definitive Dates Missing

Commas are not used if a part of a date is not present in a written sentence. Leave out a comma if only the month and year are written, or only the month and day are written. The general rule of thumb is that if any part of the date is missing, leave off the comma.


1) They were married in January 2011 in Las Vegas.

2) The date of their wedding was Jan. 14 of last year.

Commas Dividing Clauses Including Dates

If you are writing a sentence with more than one clause that involves a two-part date, such as a month and day or a month and year, a comma comes after the first clause and before the second clause. This is true regardless of whether the date is at the end of the first clause or at the end of the sentence. Normal two-part date rules apply to the date in the written sentence.


1) On March 3, she will perform in her first Broadway production.

2) He began his business studies at the beginning of his second semester, in January 2010.

Commas and Other Numbers

When discussing a number of years not directly related to a date, commas simply divide the clauses of a sentence. Do not place a comma after a number simply because it is a number.


1) We have lived in our house for 30 years.

2) In five years, we will move to Arizona.