If you're trying to determine the year of your John Deere 112 lawn tractor, there are a few things you can check. The date of manufacture should be stamped on the engine block, just below the cylinder head. If that's not visible or legible, you can also find a plate with the serial number and model number near the front of the tractor, on the left side. The first two digits of the serial number indicate the year of manufacture.
For example, if yourserial number is 1M0112DKC010121, then your tractor was made in 1981. Other than that, there's no easy way to tell what year your John Deere 112 was made without taking it apart and looking at specific component dates or contacting John Deere directly.