libsmi error date-value

Error text: date specification `__' contains an illegal value

Reference: RFC 2578 section 2

The date field specifies an invalid date (e.g. september 31st), or one
that the date manipulation routines can't handle (e.g. before 1970).

ExtUTCTime ::= OCTET STRING(SIZE(11 | 13))
    -- format is YYMMDDHHMMZ or YYYYMMDDHHMMZ
    --   where: YY   - last two digits of year (only years
    --                 between 1900-1999) 
    --          YYYY - last four digits of the year (any year)
    --          MM   - month (01 through 12)
    --          DD   - day of month (01 through 31)
    --          HH   - hours (00 through 23)
    --          MM   - minutes (00 through 59)
    --          Z    - denotes GMT (the ASCII character Z)