anchor.diff:  !
   !======================================================================>
   
  +  ! ARGUMENTS:
     CLASS(datetime),INTENT(IN) :: self
   
     CHARACTER(LEN=3),PARAMETER,DIMENSION(7) :: &
  
positive.code: !
  !======================================================================>
  
    INTEGER,INTENT(IN) :: year
  
    IF(isLeapYear(year))THEN
  
negative.code: !
  !======================================================================>
  
    ! ARGUMENTS:
    CLASS(datetime),INTENT(INOUT) :: self
    INTEGER,        INTENT(IN)    :: ms
  
  