1. Stamped on the plate: The plate is the large, metal frame that supports the strings. On many pianos, the manufacturing date is stamped on the plate, usually near the tuning pins.
2. Printed on the keyslip: The keyslip is a thin strip of paper or plastic that is attached to the front of the keyboard. On some pianos, the manufacturing date is printed on the keyslip.
3. Found in the owner's manual: If you have the original owner's manual for your piano, it may include the manufacturing date.