code: function getElapsedTimeString(start_timestamp_ms, updated_timestamp_ms) {
    var updatedDiff = updated_timestamp_ms - start_timestamp_ms;
    var updatedDays = Math.floor(updatedDiff / 86400000.0);
    updatedDiff -= (updatedDays * 86400000.0);
    var updatedHours = Math.floor(updatedDiff / 3600000.0);
    updatedDiff -= (updatedHours * 3600000.0);
    var updatedMinutes = Math.floor(updatedDiff / 60000.0);
    updatedDiff -= (updatedMinutes * 60000.0);
    var updatedSeconds = Math.floor(updatedDiff / 1000.0);
  
    var updatedString = '';
    if (updatedDays == 1) {
      updatedString = '1 day, ';
    } else if (updatedDays > 1) {
      updatedString = '' + updatedDays + ' days, ';
    }
    updatedString +=
        leftPadNumber(updatedHours, 2, '0') + ':' +
        leftPadNumber(updatedMinutes, 2, '0') + ':' +
        leftPadNumber(updatedSeconds, 2, '0');
  
    return updatedString;
  }
docs: Get locale time string for time portion of job runtime. Specially handle number of days running as a prefix.