Charlie Brown's birthday

Charlie Brown's birthday
Charles Brown / C. Brown / Chuck Brown
1950-10-30 (Confirmed)
http://www.gocomics.com/peanuts/1950/10/30

Linus was born in October.
195x-10-05
http://www.gocomics.com/peanuts/1986/06/09
http://peanuts.wikia.com/wiki/June_1986_comic_strips?file=Pe860609.gif

Lucy
"Lucy's birthday is heavily mentioned throughout the strip, especially in the fifties and early sixties (1959-04-11, 1962-04-09, 1963-04-07). Though there is no specific date when it is, it is mentioned constantly throughout March and April, meaning that she could possibly be an Aries."

Sally
1959-05-26 (Confirmed)
http://www.gocomics.com/peanuts/1959/05/26
https://vignette.wikia.nocookie.net/peanuts/images/f/f3/Pe590526.gif/revision/latest?cb=20130819164836

Peppermint Patty
1970-10-04 (Confirmed)
http://www.gocomics.com/peanuts/1970/10/04
http://peanuts.wikia.com/wiki/October_1970_comic_strips?file=Pe701004.jpg

Rerun
1972-05-23 (Confirmed)
http://www.gocomics.com/peanuts/1972/05/23

Schroeder
1954-01-18 (Confirmed)
http://www.gocomics.com/peanuts/1954/01/18

Woodstock 1970-05-21 (Confirmed by Schulz Museum USA on 2020-07-13) 

http://www.gocomics.com/peanuts/1970/05/21

 
Marcie
1990-11-09
http://www.gocomics.com/peanuts/1990/11/09

Franklin 1968-07-31(?)

Patty
1950-12-04 (Confirmed)
http://www.gocomics.com/peanuts/1950/12/04

Violet
1955-01-28 (Confirmed)
http://www.gocomics.com/peanuts/1955/01/29

Snoopy 1968-08-10!!