How to Display Only the Date of Last Row Modification in a "Date Changed" Column?

System

This discussion was created from comments split from: Checkmark in one column to show a completed date on a second column and it stays that date.

Penguin

I don't need an actual time stamp, just the date.
When anything in the row changes, I would like the cell in a "Date Changed" column to show the date it was modified. When something else changes in the row, the date will change until there was another modification to that row.

Paul Newcome

@Penguin I would leave the modified date/time stamp in the sheet and hide it then use a regular date type column with a DATEONYL function.

=DATEONY([Modified Date]@row)

Penguin

Ok, what is the best "if" formula to get the date/time stamp in a hidden cell?

Paul Newcome

The date / time stamp would come from the system generated Modified (date) column.