date.h:20:  Is this a non-const reference? If so, make const or use a pointer: int& y  [runtime/references] [2]
date.h:20:  Is this a non-const reference? If so, make const or use a pointer: int& m  [runtime/references] [2]
date.h:20:  Is this a non-const reference? If so, make const or use a pointer: int& d  [runtime/references] [2]
date.h:34:  Constructors callable with one argument should be marked explicit.  [runtime/explicit] [5]
date.h:59:  Line ends in whitespace.  Consider deleting these extra spaces.  [whitespace/end_of_line] [4]
date.h:59:  Redundant blank line at the start of a code block should be deleted.  [whitespace/blank_line] [2]
Done processing date.h
Total errors found: 6