How do I setup an Apps Script to OnEdit() paste Values (into another column) based on certain Triggers

Background (of the request):

Columns F-H are small excerpt of a Manpower spreadsheet.

Every shift is full of Start Time "Adjustments" ...and the ability to make adjustments to Employee "Start Times" in the Table (Columns F-H) ...while and Apps Script makes adjustments to the raw data (Columns A-E) is the key 🗝️

I'm hoping the Step By Step Markdown Table section proves helpful. Aside from that, there is a Link to Google Sheet ⤵️ ...and a GIF showing a simple Start Time Adjustment is also provided.

Apps Script pastes Value (into another column) when "Result" value is different than "Start" (value)

Start: Table consists of Cells A1 to H7

Step 1 >> 1:00pm << is entered into Cell F4 ** note: value in C4 [1:00pm] no longer matches B4 [3:00pm] **

Step 2: (unmatching) value in C4 is "Manually" entered into D4 >> 1:00pm <<

Step 3: >> Employee B << is Cut/Pasted into Cell G5

Formula in F5 recognizes "Manual" entry in D4 and displays >> 1:00pm << (in Cell F5)

Step 4: Cell F5 is changed from 1:00pm to >> 8:00pm <<

Cells D4 [1:00pm] & C4 [8:00pm] are compared [Do Not Match]

Step 5: (unmatching) value in C4 is "Manually" entered into D4 >> 8:00pm <<

Instead of "Manually" entering the value into "Column D" ...is it possible

1. To have a Apps Script check for 'when' the values in Columns B & C do NOT match, and "Automatically"
2. Populate Column E with the value from Column C (rather than manually inputting the value into Column D), and
3. When there's a value in Column E, the Apps Script then checks for 'when' the values in Columns C & E do not match, and then
4. Overwrites 'whatever' value is in Column E with the value from Column C (so they match), and then
5. Every time the values in Columns C & E do not match 'afterward' ...the Apps Script continues overwriting the value Column E with the value from Column C?

Here's a GIF 'attempting' to summarize the request:

Automatically copy the data if a certain condition matches

I have crafted a Google Apps script which I believe would solve your request. From the GIF you've shared, you only enter values within col F and G. therefore I set the column F as a trigger point wherein if you enter a value in col F. it will then activate the condition of checking whether the values from col B and C matches. if it doesn't, it will copy the values to Col E. However, I have noticed there are columns where you use formulas to copy values (Column C and F). Please note that this could be a limitation to Apps script, I would suggest that you try to use apps script for complete automation instead.

Try this code:

function onEdit(e) {
  var sheet = e.source.getActiveSheet();
  var range = e.range;

  if (range.getColumn() === 6) { 
    var editedRow = range.getRow();
    var aTeam = sheet.getRange(editedRow, 7).getDisplayValue(); 

    if (!aTeam) return; 

    var lastRow = sheet.getLastRow();
    var empName = sheet.getRange(3, 1, lastRow - 2, 1).getValues(); 
    
    var targetRow = -1;
    for (var i = 0; i < empName.length; i++) {
      if (empName[i][0] === aTeam) {
        targetRow = i + 3; 
        break;
      }
    }

    if (targetRow !== -1) {
      var colB = sheet.getRange(targetRow, 2).getDisplayValue(); 
      var colC = sheet.getRange(targetRow, 3).getDisplayValue(); 

      if (colB !== colC) {
        sheet.getRange(targetRow, 5).setValue(colC);
      }
    }
  }
}

NOTE: after running the code, you'll see some expected errors. Try to edit or add values in column F to see if it meets your expected result. Additionally, if you will add another name or entry in col A to C, you should always copy and paste the formula you have within col C to copy the data from col F.

Reference: onEdit(e)