Google Apps Script macro to clear contents in a Google Sheet, skipping protected columns and rows

clearContents.gs

/** @OnlyCurrentDoc */

clearTransactions(3, 1, 6, 6, true);

function clearTransactions(nHeaderRows, nHeaderColumns, nAccountsPerSection, nRowsPerDay, DEBUG = false) {

  // BEGIN https://stackoverflow.com/a/21231012/2925434
  function columnToLetter(column) {
    var temp, letter = '';
    while (column > 0) {
      temp = (column - 1) % 26;
      letter = String.fromCharCode(temp + 65) + letter;
      column = (column - temp - 1) / 26;
    }
    return letter;
  }
  // END https://stackoverflow.com/a/21231012/2925434

  // Google Sheets columns are numbered starting from 1
  var sheet = SpreadsheetApp.getActive().getSheetByName("daily");

  // get protected columns
  var maxColumn = sheet.getLastColumn();
  var protectedColumns = [];

  function isProtectedColumn(index) {
    return index <= nHeaderColumns || (index - nHeaderColumns) % (nAccountsPerSection + 1) == 0;
  }

  for (var col = 1; col <= maxColumn; ++col) {
    if (isProtectedColumn(col)) {
      protectedColumns.push(col);
    }
  }

  if (DEBUG) {
    Logger.log("protected columns: " + protectedColumns.map( each => columnToLetter(each) ));
  }

  // get protected rows
  var maxRow = sheet.getLastRow();
  var protectedRows = [];

  function isProtectedRow(index) {
    return index <= nHeaderRows || (index - nHeaderRows) % (nRowsPerDay + 1) == 0;
  }

  for (var row = 1; row <= maxRow; ++row) {
    if (isProtectedRow(row)) {
      protectedRows.push(row);
    }
  }

  if (DEBUG) {
    Logger.log("protected rows: " + protectedRows);
  }

  var ranges = [];

  for (var top = 0; top < (protectedRows.length - 1); ++top) {
    var topIncl = protectedRows[top] + 1;
    var botIncl = protectedRows[top+1] - 1;
    if (botIncl - topIncl < 0) { continue; }

    for (var left = 0; left < (protectedColumns.length - 1); ++left) {
      var leftIncl = protectedColumns[left] + 1;
      var rightIncl = protectedColumns[left+1] - 1;
      if (rightIncl - leftIncl < 0) { continue; }

      var range = columnToLetter(leftIncl) + topIncl + ":" + columnToLetter(rightIncl) + botIncl;

      if (DEBUG) {
        Logger.log("range " + range + " will be cleared when DEBUG == false");
      } else {
        ranges.push(range);
        // currently no way to clear comments
        sheet.getRangeList(ranges).clearContent();
      }
    }
  }

}