public final function getDifferenceYears( $dt = null, bool $abs = true ) : int
   {

      $dt = $dt ?: static::Now( $this->getTimezone() );

      return (int) $this->diff( $dt, $abs )->format( '%r%y' );

   }
public final function getDifferenceYears( $dt = null, bool $abs = true ) : int
   {

      $dt = $dt ?: static::Now( $this->getTimezone() );

      return (int) $this->diff( $dt, $abs )->format( '%r%y' );

   }
public final function getDifferenceYears ( $ dt = null , bool $ abs = true ) : int { $ dt = $ dt ? : static :: Now ( $ this -> getTimezone ( ) ) ; return ( int ) $ this -> diff ( $ dt , $ abs ) -> format ( '%r%y' ) ; }
Get the difference in years between current date time and defined.

If no other date time is defined Now is used.

@param \Beluga\Date\DateTime|null $dt
@param bool                       $abs Get the absolute of the difference
@return int
Get the difference in years between current date time and defined .