The YEAR type is a 1-byte type used to
        represent year values. It can be declared as
        YEAR with an implicit display width of 4
        characters, or equivalently as YEAR(4) with
        an explicit display width.
          he YEAR(4) data type using an
          explicit display width is deprecated and you should expect
          support for it to be removed in a future version of MySQL.
          Instead, use YEAR without a
          display width, which has the same meaning.
        MySQL displays YEAR values in
        YYYY format, with a range of
        1901 to 2155, and
        0000.
      
        YEAR accepts input values in a variety of
        formats:
- As 4-digit strings in the range - '1901'to- '2155'.
- As 4-digit numbers in the range - 1901to- 2155.
- As 1- or 2-digit strings in the range - '0'to- '99'. MySQL converts values in the ranges- '0'to- '69'and- '70'to- '99'to- YEARvalues in the ranges- 2000to- 2069and- 1970to- 1999.
- As 1- or 2-digit numbers in the range - 0to- 99. MySQL converts values in the ranges- 1to- 69and- 70to- 99to- YEARvalues in the ranges- 2001to- 2069and- 1970to- 1999.- The result of inserting a numeric - 0has a display value of- 0000and an internal value of- 0000. To insert zero and have it be interpreted as- 2000, specify it as a string- '0'or- '00'.
- As the result of functions that return a value that is acceptable in - YEARcontext, such as- NOW().
        If strict SQL mode is not enabled, MySQL converts invalid
        YEAR values to 0000. In
        strict SQL mode, attempting to insert an invalid
        YEAR value produces an error.
      
See also Section 13.2.9, “2-Digit Years in Dates”.