How can I compare a date in a Google Sheets cell to today? - Apps Script

I am very new to Apps Script, so forgive me if this is super simple, but here's a rundown of what I'm trying to do:
(please keep in mind I've tried so many different ways to do this, and have been reading and trying this for a week lol)

I have a sheet with an "end date" column (G:G). (MMDDYYY)
The next column over is the "status" column (H:H) with a dropdown, and one of the options is "Update Status."

I'm trying to get the "status" column to say "Update Status" when the end date is in the past.

Unfortunately, I can't link the sheet because it has confidential information, but here's a screenshot of the columns:
(https://i.stack.imgur.com/xW1o9.png)

Here's the latest script I've tried:

function updateStatus()
{
  var ss = SpreadsheetApp.getActiveSpreadsheet(); //get the spreadsheet
  var sheet = ss.getSheetByName('February 2023'); //get the Feb sheet
  var rangeG = sheet.getRange('G:G'); // get the end date row
  var endDates = rangeG.getValues(); // get the values
  var status = sheet.getRange('H:H');
  var day = 24*3600*1000
  var today = parseInt((new Date().setHours(0,0,0,0))/day); // get date today
  
  for (var i = 0; i < endDates.length; i++) { // repeat loop
    var dataday = parseInt(endDates[i][0].getTime()/day)
    
      if (dataday < today){
        status.setValue('Update Status');
    }
  }
}

Literally nothing happens. For this one, I referenced: https://stackoverflow.com/questions/14350671/how-do-i-compare-dates-with-a-spreadsheet-using-google-apps-script

Try this:

function updateStatus() {
  const ss = SpreadsheetApp.getActiveSpreadsheet();
  const sh = ss.getSheetByName('February 2023');
  const rg = sh.getRange('G1:G' + sh.getLastRow());
  const ds = rg.getValues().flat();
  const status = sh.getRange('H1:H' + sh.getLastRow()).getDisplayValues();
  const dt = new Date();
  const today = new Date(dt.getFullYear(), dt.getMonth(), dt.getDate()).valueOf();
  ds.forEach((e, i) => {
    if (new Date(e).valueOf() < today) {
      sh.getRange(i + 1, 8).setValue('Update Status');
    }
  });
}

From your provided sample image, it seems that the 1st row is a header row. And, in your script, the values are retrieved from the 1st row. By this, I think that an error occurs at endDates[i][0].getTime() for the 1st row. But, you say Literally nothing happens.. So, I'm worried that you might have miscopied your script.

So, in this answer, I would like to propose a sample script for achieving your goal. The sample script is as follows.

Sample script:

function updateStatus() {
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var sheet = ss.getSheetByName('February 2023');
  var range = sheet.getRange('G2:H' + sheet.getLastRow());
  var now = new Date();
  now.setHours(0, 0, 0, 0);
  var today = now.getTime();
  var values = range.getValues().map(([g, h]) => [g.getTime() < today ? 'Update Status' : h]);
  range.offset(0, 1, values.length, 1).setValues(values);
}

• When this script is run, the values are retrieved from the columns "G" and "H", and check the date of column "G". When the date is the past from today, "Update Status" is put to the column "H". And, when the date is not the past from today, the current value of column "H" is left.

• If you want to remove the value when the date is not the past from today, please modify g.getTime() < today ? 'Update Status' : h to g.getTime() < today ? 'Update Status' : null.

Reference:

• map()

Try:

function updateStatus() {
  var ss = SpreadsheetApp.getActiveSpreadsheet(); //get the spreadsheet
  var sheet = ss.getSheetByName('February 2023'); //get the Feb sheet
  var rangeG = sheet.getRange('G2:G' + sheet.getLastRow()); // get the end date row
  var endDates = rangeG.getValues(); // get the values
  var day = 24 * 3600 * 1000
  var today = parseInt((new Date().setHours(0, 0, 0, 0)) / day)

  for (var i = 0; i < endDates.length; i++) { // repeat loop
    var dataday = parseInt(endDates[i][0].getTime() / day)
    if (dataday < today) {
      sheet.getRange(i + 2, 8).setValue('Update Status');
    }
  }
}

Result:

Using your code you may change the following:

From:

var rangeG = sheet.getRange('G:G'); // get the end date row

To:

var rangeG = sheet.getRange('G2:G' + sheet.getLastRow()); // get the end date row

This will get rid of the error: TypeError: endDates[i][0].getTime is not a function. You are getting this error because you are including the header which is not a date, so adjust this to start on row 2 which is the actual date.

And

From:

status.setValue('Update Status');

This will change the whole "status" (Column H) to Update Status.
To:

sheet.getRange(i + 2, 8).setValue('Update Status');

The value i is the row number. You started with 0 so you add 2 to start on row 2.