function onEdit() {
var s = SpreadsheetApp.getActiveSheet();
if( s.getName() == "Sheet1" ) { //checks that we're on the correct sheet
var r = s.getActiveCell();
if( r.getColumn() == 1 ) { //checks the column
var nextCell = r.offset(0, 5);
//if( nextCell.getValue() !== '' ) //is empty?
nextCell.setValue(new Date());
}
if( r.getColumn() == 7 ) { //checks the column
var nextCell = r.offset(0, 5);
//if( nextCell.getValue() !== '' ) //is empty?
nextCell.setValue(new Date());
}
if( r.getColumn() == 13 ) { //checks the column
var nextCell = r.offset(0, 5);
//if( nextCell.getValue() !== '' ) //is empty?
nextCell.setValue(new Date());
}
if( r.getColumn() == 19 ) { //checks the column
var nextCell = r.offset(0, 5);
//if( nextCell.getValue() !== '' ) //is empty?
nextCell.setValue(new Date());
}
if( r.getColumn() == 25 ) { //checks the column
var nextCell = r.offset(0, 5);
//if( nextCell.getValue() !== '' ) //is empty?
nextCell.setValue(new Date());
}
}
}