That would depend on what sort/make/model of mower it was and what country it was made (and possibly sold) in.
04072157
Write down the serial number which should be printed on a serial number tag somewhere on the mower. Take the number to your local John Deere dealer and they should be able to tell you what year your mower was produced.
I have been told it is the first two numbers in your serial number.
2004
To determine the year of a John Deere 757 track mower with a specific serial number starting with "OTC," you would typically need to refer to John Deere's serial number lookup resources or contact a John Deere dealer. Serial numbers often contain information about the production year and model, but without the full serial number, it's not possible to pinpoint the exact year. Generally, John Deere equipment has a standard method for decoding the year from the serial number.
1998
To find the date of manufacture for a Poulan lawn mower, locate the model and serial number, usually found on a sticker or metal plate on the mower's frame or engine. The serial number often includes a date code; the first few digits may indicate the year and week of manufacture. You can also check the Poulan website or contact their customer service with the model and serial number for specific information. Additionally, user manuals may provide insights on decoding the serial number.
The Craftsman lawn mower model 917.289250 was typically produced around 2003. Craftsman model numbers often include the year of manufacture in their serial numbers, so the specific year can be confirmed by checking the serial number on the mower. For precise identification, it’s best to refer to the owner's manual or contact Craftsman directly with the model number.
the first two numbers is the year last two should be the size cut
You have given the serial number rather than the model number. Perhaps MTD could answer that, but I doubt anyone else could.
Depending on when it was built. If it was recently the year will be the first six digits of the serial number. 2 for month 2 for day and 2 for year in that order.
To determine the year of a Dixon mower, locate the model and serial number, typically found on the frame or under the seat. You can then refer to the manufacturer's website or contact their customer service for assistance in decoding the serial number. Additionally, some mowers have a date code stamped on the engine or other components that can indicate the year of manufacture. Always check the user manual for specific guidelines related to your model.