How Jerry Reuss figures out the dates on his cards

Yesterday I posted Jerry Reuss's 1984 Topps card, which on his flickr account he notes was taken on May 20, 1983. Reader John posted a question in the comments section, "How does he know that. He is able to tell the stadium from this background?"

Jerry saw the question and has this response for John and anyone else who was wondering:
"I saw the comment on the blog and have an answer for John. For the most part, I can identify the ballparks where the photos were taken. Since the card was released in 1984, the picture was taken in 1983 or earlier. Then it's a matter of deductive reasoning using retrosheet.org. If it was a day game as it was in this shot, I see that I faced the Mets in Shea on Saturday afternoon, 5/20/1983.

When all else fails, I simply look at the date on the slide or 35 mm negative as I've catalogued nearly all of them that I used for my Flickr account. The negative for this picture was from a roll taken in 1983. As you can guess, I have a lot of time on my hands!"

Thanks!

As for figuring out the stadium, one way to learn the ballparks is to see what the cards of players in their home uniforms look like, and comparing them to those with players in road uniforms. I kind of learned this without trying by spending so much time looking at my cards when I was a kid.