I just found this old file that I saved on January 18, 2010. I must have copied this information from an old version of the official Archie site:

February 7

Jughead

March 19

Veronica

March 30

Geraldine Grundy

April 5

Waldo Weatherbee

April 7

Benjamin Flutesnoot

April 27

Hiram Lodge

May 3

Nancy

May 8

Hermione Lodge

June 8

Chuck

June 10

Fred Andrews

June 21

Mr. Svenson

June 29

Betty

July 4

Midge

July 20

Moose

July 25

Reggie

August 18

Terry "Pop" Tate

September 1

Ms. Beazly

September 21

Dilton

December 3

Mary Andrews

December 7

Archie

Interesting the only issue I saw where they even mentioned a birthday was a Veronica Fish issue. Reggie wanted a fake id. And it showed a birthday for him.