Troubleshoot Google Script for Hiding Columns based on date range

Question

CORRECTED

I have a google sheet with a table of weekly data (one year's worth).

https://docs.google.com/spreadsheets/d/1u5o0rqEFTiGcZygtbMcohuQAWn6AxfXF78c4Vjp2D8g/edit#gid=84545445

At the top of the sheet I have "to" and "from" date fields.

I am trying to restrict the user's view by hiding all columns which relate to dates outside of the "to"/"from" range.

I have researched how to do this but am clearly unable to craft the script correctly.

UPDATE I have now corrected this but my script will only hide the first column no matter what dates I have in the "to"/"from" cells. Script exactly as below.

Thank you.

function onOpen() {
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var s = ss.getSheetByName('NEW - HOURS'); 
  var startColumn = 5; 
  var values = s.getRange('E7:BD7').getValues(); 
  var start = s.getRange('B4').getValue();
  var end = s.getRange('B5').getValue();
  var column, len, date, hideCount = 0, showCount = 0;

  for (column = values.length - 1; column >= 0; --column) {
    date = values[column][0];

    if ( typeof date != 'object' ||  !(date >= start && date < end) ) {
     if (showCount) {
        s.showColumns(column + startColumn + 1, showCount);
        showCount = 0;
      }
      hideCount++;
    } else {
      if (hideCount) {
        s.hideColumns(column + startColumn + 1, hideCount);
        hideCount = 0;
      }
      showCount++;
    }
  }
  if (showCount) s.showColumns(column + startColumn + 1, showCount);
  if (hideCount) s.hideColumns(column + startColumn + 1, hideCount);
}

Answer 1

Mind the row-column notation

Be aware that a range is a 2-dimensional array, where the outer array corresponds to the rows, and the nested array to the columns, as can be withdrawn from the method getRange(row, column).

As a consequence, the values matrix is defined as values[row][column], and values.length will give you the number of rows - for the number of columns use values[0].length.

In summary, you need to change

for (column = values.length - 1; column >= 0; --column) {
    date = values[column][0];
    ...

to

  for (column = values[0].length - 1; column >= 0; --column) {
    date = values[0][column];
    ...

ADDITIONAL UPDATE:

    function onOpen() {
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var s = ss.getSheetByName('NEW - HOURS'); 
  var startColumn = 5; 
  var values = s.getRange('E7:7').getValues();