function SetCalendar() {
  //The indexes of the first row and the first column in the data table
  const rowStart = 1;
  const colStart = 1;

  //The number of rows and columns in the schedule
  const colsCount = 4;
  const rowsCount = 3;  

  //Getting the page
  var sheet = SpreadsheetApp.getActiveSheet();

  //Extracting table data within the specified ranges
  var range = sheet.getRange(rowStart, colStart, rowsCount, colsCount)
  var data = range.getDisplayValues();

  //Constants for column indexes
  const dateCol = 0;
  const timeCol = 1;
  const nameCol = 2;
  const placeCol = 3;

  //savedDate — In variable, we store the last read date!
  let savedDate = "";
  //We access the data with variable i, where the loop iterates and retrieves the value
  //(which is an index), ultimately returning the row (the current row of the table)
  for (var i in data) {
    let row = data[i];

    let classDate = row[dateCol]; //row[dateCol] — we extract the date from the dateCol column.
    let classPeriod = row[timeCol];
    let className = row[nameCol];
    let classPlace = row[placeCol];

    if (classDate.trim() == "") {
      //If the date is an empty string, then we take the date from the savedDate variable.
      classDate = savedDate;
    } else {
      //Otherwise, we update the value of savedDate
      savedDate = classDate;
    }
    
    //We get the start and end date-time of the event
    let classTimeInfo = extractPeriod(classPeriod, classDate);

    let classStartTime = classTimeInfo.from;
    let classEndTime = classTimeInfo.to;

    //Merge all additional information
    let info = "Place: " + classPlace;

    //We access Google Calendar through methods of the global object CalendarApp
    //We use the getCalendarsByName method to obtain an array of calendars 
    //with the specified name, mine is named 'Important Matters'
    //From the array, we need to take one element, which is the zeroth [0] element.
    var event = (CalendarApp.getCalendarsByName("Important Matters"))[0].createEvent
    (
      className,
      classStartTime,
      classEndTime,
      {
        //description of the event, which we earlier stored in the variable 'info'
        description: info
      }
    );
    //As sometimes frequent calls to the Google Calendar service might cause issues,
    //it is recommended to introduce a delay between method calls to the calendar
    Utilities.sleep(50);
  }
}

function extractTime(timeStr, dateStr) {
  //It splits the time string into hours and minutes based on the colon (:) separator.
  let sepIdx = timeStr.indexOf(":");

  let hoursStr = timeStr.substring(0, sepIdx);
  let minsStr = timeStr.substring(sepIdx + 1);

  //It splits the date string into day, month, and year based on the slash (/) separator.
  sepIdx = dateStr.indexOf("/");

  let dayStr = dateStr.substring(0, sepIdx);
  let monthStr = dateStr.substring(sepIdx + 1, sepIdx + 3);

  sepIdx = dateStr.indexOf("/", sepIdx + 1);

  let yearStr = dateStr.substring(sepIdx + 1);
  
  //Note that the month is adjusted by subtracting 1 
  //since months in JavaScript Date objects are zero-indexed 
  //(January is 0, February is 1, and so on).
  let t = new Date();
  t.setHours(parseInt(hoursStr), parseInt(minsStr));
  t.setYear(parseInt(yearStr));
  t.setMonth(parseInt(monthStr) - 1, parseInt(dayStr));

  return t;
}

function extractPeriod(periodStr, dateStr) {
  //It finds the index of the hyphen '-' in the period string 
  //to separate the start and end times.
  let sepIdx = periodStr.indexOf("-");

  let fromStr = periodStr.substring(0, sepIdx);
  let toStr = periodStr.substring(sepIdx + 1);
  
  //It trims any leading or trailing whitespace from both time strings.
  fromStr = fromStr.trim();
  toStr = toStr.trim();

  return {
    from: extractTime(fromStr, dateStr),
    to: extractTime(toStr, dateStr)
  }
}