Technical Battery Date code

I have the following date code stamped into the top by the negative post: JY9I1P. Does anyone know when this battery was made by this code?

 

the batteries I buy at walmart have a sticker with month/year, pretty easy to read.

But if you don't know when the battery was replaced, either because someone else did it or you forgot, it's probably time for a new one, if it acts like it's bad.

(I've seen stamped date codes that were letters and numbers, but they usually make sense for year/ month)

 

This will help. I think your battery is: Jan 2011. JY means January, 11 means year 2011, P means plant that made the battery. Look at this video.
Bing Videos

 

well past the sell by date. Interesting, hadn't seen the two letter code for month like that before on electric stuff.

 

I'm guessing it's 2021, cuz it still starts the car.