I am not sure how efficient this is, but the following script appears to be doing what I intended.
I would still appreciate ant help this forum can offer in improving it.
Your code looks fine - you should probably check whether the edited cell is in the appropriate column (unless you’re already doing that, higher up in the script). Also, you can combine your UPDATE statements into one call - just combine the two columns:
onCellEdited passes a colName parameter to you, which you could check to make sure the column that was edited is one of the columns you expect - although, actually, what I thought might happen (circular referencing, where editing ‘complete’ edits ‘t_stamp’ and fires the script again) won’t actually happen due to the way onCellEdited works.
First I simplified my query as you suggested. Still works great. But enters the Time when any cell is edited. Then I made some (rookie) attempts at targeting the column “Complete”. So far no luck.
if colName == ‘complete’: