Using OnEdit to add Date to Previous Cell in Google Sheets

Here's a nifty bit of code that will add a Date to the cell of your row when you enter data in the 3rd cell.

function onEdit(e) {

 

    var ss = e.source.getActiveSheet();

    if (ss.getName() !== 'sheet1' || e.range.columnStart !== 2) return;

    e.range.offset(0, -1)

        .setValue(e.value ? new Date() : null);

}

Or if you want to have it on a couple of sheets you could use

function onEdit(e) {

 

    var ss = e.source.getActiveSheet();

  if (ss.getName() == 'sheet1' && e.range.columnStart == 2) {

    e.range.offset(0, -1)

        .setValue(e.value ? new Date() : null);

  }

  else if (ss.getName() == 'sheet3' && e.range.columnStart == 2){

    e.range.offset(0, -1)

        .setValue(e.value ? new Date() : null);

  }

  else if (ss.getName() == 'sheet5' && e.range.columnStart == 2){

    e.range.offset(0, -1)

        .setValue(e.value ? new Date() : null);

  }

  else {

   return; 

  }

  

}