Google Sheets function to calculate time averages and best times

time_calculations.gs

/**
* Averages time provide in formate minutes:seconds:millisec
 *
 * @param {range} input The value to multiply.
 * @return The average of input range.
 * @customfunction
 */
function AVERAGETIME(input) {
  if (!input.map) //test if it is not an array
    return input
    
  var total_time = 0;
  var total = input.length;
    
  for (var i =0 ; i<total; i++){
    var time = getTimeInMicroSeconds(input[i]);
    total_time += time;    
  }
  
  var average_time = Math.floor(total_time/total);
  var microseconds = average_time % 100;
  var seconds = Math.floor(average_time/100) % 60;
  var minutes = Math.floor(average_time/6000);
  return correctSizeString(minutes,2)+"."+correctSizeString(seconds,2)+"."+correctSizeString(microseconds,2);
}

function BESTTIME(input) {
  if (!input.map)
    return input;
 
  minimum_time = Infinity;
  index_minimum = -1;
  
  for (var i=0; i<input.length; i++) {
    var time = getTimeInMicroSeconds(input[i]);
    if (time < minimum_time){
      minimum_time = time;
      index_minimum = i;
    }
  }
  return input[index_minimum];
}

function getTimeInMicroSeconds(timeGiven) {
  var time = String(timeGiven).split('.');
  return parseInt(time[0])*6000 + parseInt(time[1])*100 + parseInt(time[2]);
}

function correctSizeString(time, length){
  var strTime = time.toString();
  while (strTime.length < length){
    strTime = "0" + strTime;
  }
  return strTime;
}