Thanks, joerat1!
Here are your 25 calendar dates:
January 10, 2020 - Willie McCovey
February 20, 2020 - Jack Bolling
March 5, 2020 - Sam Thompson
March 22, 2020 - Edwin Diaz
March 28, 2020 - Mark Melancon
April 3, 2020 - Koji Uehara
April 21, 2020 - Gary Peters
April 28, 2020 - Barry Larkin
May 10, 2020 - Chippy McGarr
May 15, 2020 - George Brett
May 17, 2020 - Elmer Steele
June 6, 2020 - Bill Dickey
June 27, 2020 - Eddie Kasko
June 28, 2020 - Ken Williams
August 5, 2020 - Ray Pepper
September 5, 2020 - Nap Lajoie
September 24, 2020 - Hunter Strickland
September 30, 2020 - Kenley Jansen
October 8, 2020 - Wally Moses
October 17, 2020 - Buck Ewing
November 10, 2020 - Cy Morgan
November 17, 2020 - Tom Seavet
November 23, 2020 - Luis Tiant
December 7, 2020 - Shane Mack
December 9, 2020 - Jim Merritt
They were picked randomly out of 366 possible dates between January 1, 2020 and December 31, 2020.
Timestamp: 2020-01-19 15:21:46 UTC