const horaires = [{ heure_depart: '21:00', numero_train: '123' }];
const isArrival = false;
const currentTime = new Date();
currentTime.setHours(20, 55, 0, 0);

for (const train of horaires) {
  const numTrain = train.num_train || train.numero_train || train.numero;
  const timeStr = isArrival 
          ? (train.heure_arrivee || train.arrival_time || train.time || train.heure) 
          : (train.heure_depart || train.departure_time || train.time || train.heure);
  
  let trainTime;
  if (typeof timeStr === 'string' && timeStr.length <= 5 && timeStr.includes(':')) {
           const [hh, mm] = timeStr.split(':');
           trainTime = new Date(currentTime);
           trainTime.setHours(parseInt(hh, 10), parseInt(mm, 10), 0, 0);
  } else {
           trainTime = new Date(timeStr);
  }
  const diffMs = trainTime.getTime() - currentTime.getTime();
  const diffMins = Math.floor(diffMs / 60000);
  console.log(`numTrain=${numTrain}, timeStr=${timeStr}, diffMins=${diffMins}`);
}