Diferença em horas sendo calculada incorretamente

private double diferencaHoras(Date horaEntrada, Date horaSaida){
		 double result = 0;  
         long diferenca = horaSaida.getTime() - horaEntrada.getTime();  
         long diferencaEmHoras = (diferenca /1000) / 60 / 60;  
         long minutosRestantes = (diferenca / 1000)/60 %60;  
         double horasRestantes = minutosRestantes / 60d;  
         result = diferencaEmHoras + (horasRestantes); 
         return result;
	}
	
	public static void main(String[] args){
		HorarioServiceImpl h = new HorarioServiceImpl();


		Date data1 = new Date();
		data1.setDate(15);
		data1.setMonth(10);
		data1.setYear(1987);
		data1.setHours(9);
		data1.setMinutes(10);
		data1.setSeconds(30);
		
		Date data2 = new Date();
		data2.setDate(15);
		data2.setMonth(10);
		data2.setYear(1987);
		data2.setHours(17);
		data2.setMinutes(54);
		data2.setSeconds(30);
	
		System.out.println(h.diferencaHoras(data1, data2));
		
	}