「乗換駅に着いたら次の電車までの時間を声で知らせてくれる」のためのGoogle Apps Scriptのコード．Google Spreadsheetの時刻と，時刻表データをもとに動作する．

notifyNextTrainTime.js

Const = {
  colNoFromNearHomeWeekday: 0, //時刻表シートの何列目に「平日」，「自宅側からきたとき（＝会社方面行き）」の時刻表データが入力されているか
  colNofromNearOfficeWeekday: 1,
}

var sheetTransferStationLog = SpreadsheetApp.getActive().getSheetByName('log'); //乗換駅の到着時刻のログが入力されたシート（時刻はIFTTTのLocationトリガーで自動入力させる）
var sheetTimetableStationLog = SpreadsheetApp.getActive().getSheetByName('timetable'); //時刻表のシート（時刻は予め手動で入力しておく）

var ssNearOfficeStation = SpreadsheetApp.openById('XXXXXXXXXXXXXXXXX'); //会社側の駅の到着時刻のログのスプレッドシート
var sheetNearOfficeStation = ssNearOfficeStation.getSheetByName('シート1');                          //会社側の駅の到着時刻のログのシート
var ssNearHomeStation = SpreadsheetApp.openById('XXXXXXXXXXXXXXXXX');   //家側の駅の到着時刻のログのスプレッドシート
var sheetNearHomeStation = ssNearHomeStation.getSheetByName('シート1');                              //家側の駅の到着時刻のログのシート


function myFunction(){ //この関数を「値の変更」のトリガーで実行されるように設定する
  addTime(); //到着時刻をシートに自動入力する
  notifyNextTrainTime();　//次の電車の発車時刻をwebhookする
}


//次の電車の発車時刻をwebhookする
function notifyNextTrainTime() {  
  var direction = fromWhichStation();

  if(direction == "fromNearHomeStation" || direction == "fromNearOfficeStation"){
    var value1 = searchNextTrainTime(direction);
    if(direction == 'fromNearHomeStation'){
      var value2 = '会社方面行き'
    }else if(direction == 'fromNearOfficeStation'){
      var value2 = '自宅方面行き'
    }
    var url = "https://maker.ifttt.com/trigger/notify_next_train/with/key/XXXXXXXX?value1=" + value1 + '&value2=' + value2;
    Logger.log(url);
    UrlFetchApp.fetch(url);
  }else{
    Logger.log("他の駅を経由せずに乗換駅にきた（電車でない）");
  }
  
}


function searchNextTrainTime(direction){
  var timetable = sheetTimetableStationLog.getDataRange().getValues(); //時刻表データを一旦まるごと取り込む
  var _ = Underscore.load();
  var timetableTrans = _.zip.apply(_, timetable); //時刻表データの行と列を入れ替え　https://tonari-it.com/gas-array-underscore-zip-apply/
  
  //参考：　https://qiita.com/k_keisuke/items/c6c9201e3cbdbd27c329
  var now = new Date(); //現在時刻
  var nowHours = now.getHours();
  var nowMinutes = now.getMinutes();
  var day = now.getDay(); //曜日（？）

  //colNoTimetabｌe（時刻表の何列目を参照するか）を求める　（これは曜日と行き先による）
  if(direction == "fromNearHomeStation"){
    if (day == 0) {
      colNoTimetable = Const.colNoFromNearHomeSunday;
    } else if (day == 6) {
      colNoTimetable = Const.colNoFromNearHomeSatday;
    } else {
      colNoTimetable = Const.colNoFromNearHomeWeekday;
    }
  }else if(direction == "fromNearOfficeStation"){
    if (day == 0) {
      colNoTimetable = Const.colNofromNearOfficeSunday;
    } else if (day == 6) {
      colNoTimetable = Const.colNofromNearOfficeSatday;
    } else {
      colNoTimetable = Const.colNofromNearOfficeWeekday;
    }
  }
    
  var recent = "なし";
  var timeUntilNextTrain;
  var timeNextTrain = "none";

  for(var i = 3; i < timetableTrans[colNoTimetable].length; i++) {
    var time = timetableTrans[colNoTimetable][i];
    if(time != 0){ //空白セルは「0」で埋めておく（空白セルの判定が分からなかったので…）
      var timeHours = time.getHours();
      var timeMinutes = time.getMinutes();
      
      if (recent != "なし") {
        break;
      }
      
      if ( nowHours == timeHours ) {
        if ( nowMinutes < timeMinutes ) {
          timeNextTrain = time;
            recent = "done";
          Logger.log("timeNextTrain1:");          Logger.log(timeNextTrain);
        }
      } else if ( nowHours < timeHours) {
        timeNextTrain = time;
          recent = "done";
          Logger.log("timeNextTrain2:");          Logger.log(timeNextTrain);        
      }
    }
  }
  
  if(timeNextTrain == "none"){ //たとえば現在時刻が２３時等で，次の電車が０時台のとき
    Logger.log("現在時刻を「-24」（「-1時」）にして再度検索する");
    var nowHoursMinus = nowHours - 24;
    for(var i = 3; i < timetableTrans[colNoTimetable].length; i++) {
      var time = timetableTrans[colNoTimetable][i];
      if(time != 0){ //空白セルは「0」で埋めておく（空白セルの判定が分からなかったので…）
        var timeHours = time.getHours()
        var timeMinutes = time.getMinutes();
        
        if (recent != "なし") {
          break;
        }
        
        if ( nowHoursMinus == timeHours ) {
          if ( nowMinutes < timeMinutes ) {
            timeNextTrain = time;
            recent = "done";
          }
        } else if ( nowHoursMinus < timeHours) {
          timeNextTrain = time;
          recent = "done";
        }
      }
    }
  }

 Logger.log('timeNextTrain:');  Logger.log(timeNextTrain);
 Logger.log('now:');  Logger.log(now);
 Logger.log('timeUntilNextTrain1:');  Logger.log(timeUntilNextTrain);
  
  timeUntilNextTrain = (timeNextTrain.getHours()*60 + timeNextTrain.getMinutes()) - (now.getHours()*60+now.getMinutes());
  if(timeUntilNextTrain <0){ //日付をまたいだ場合
    timeUntilNextTrain = (timeNextTrain.getHours()*60 + timeNextTrain.getMinutes()) + 24*60 - (now.getHours()*60+now.getMinutes());
  }
  
 Logger.log('timeUntilNextTrain2:');  Logger.log(timeUntilNextTrain);
  
  var returnVar = (' '+timeUntilNextTrain).slice(-3);
  
  Logger.log('returnVar:');  Logger.log(returnVar);
  return returnVar;
}


function fromWhichStation(){
  var timeAtNearOfficeStation = lastrowValue(3,sheetNearOfficeStation);
  var timeAtNearHomeStation = lastrowValue(3,sheetNearHomeStation);
  var timeAtTransferStation = lastrowValue(3,sheetTransferStationLog);

  Logger.log("timeAtNearHomeStation:"), Logger.log(timeAtNearHomeStation);
  Logger.log("timeAtTransferStation:"), Logger.log(timeAtTransferStation);
  Logger.log("timeAtNearOfficeStation:"), Logger.log(timeAtNearOfficeStation);


  var timeDifferenceNearHomeToTransfer = (timeAtTransferStation - timeAtNearHomeStation)/(60*1000);
  var timeDifferenceNearOfficeToTransfer = (timeAtTransferStation - timeAtNearOfficeStation)/(60*1000);

  if(timeDifferenceNearHomeToTransfer >0 && timeDifferenceNearHomeToTransfer < 5){
    Logger.log("fromNearHomeStation");
    return "fromNearHomeStation";
  }else if(timeDifferenceNearOfficeToTransfer >0 && timeDifferenceNearOfficeToTransfer < 5 ){
    Logger.log("fromNearOfficeStation");
    return "fromNearOfficeStation";
  }else{
    Logger.log("none");
    return "none";
  }

}



//---時刻の自動入力--------------------------------------------------------------------
// 参考：　https://qiita.com/miso_develop/items/be562d8a823ad2639d94
function addTime() {
  setTime(2, "yyyy/M/d");
  setTime(3, "H:m:s");
  Logger.log("addTime done");
}

function setTime(col, format) {
  var lastrow = sheetTransferStationLog.getLastRow();
  //  Logger.log(lastrow);
  if (sheetTransferStationLog.getRange(lastrow, col).getValue() == "") 
    sheetTransferStationLog.getRange(lastrow, col).setValue(formatTime(new Date(), format));
}

function formatTime(date, format) {
  return Utilities.formatDate(date, 'Asia/Tokyo', format)
}

function lastrowValue(col,ss){
  var range;
  if(col==1){
    range = ss.getRange("A:A").getValues();
  }else if(col==2){
    range = ss.getRange("B:B").getValues();
  }else if(col==3){
    range = ss.getRange("C:C").getValues();
  }else{
    Logger.log("ERROR: col No of lastrowValue");
  }
  var lastRow = range.filter(String).length;
  
  Logger.log(lastRow);
  
  range = ss.getRange(lastRow, col);
  return range.getValue();
}