A new date helps only when it rides on a real, substantive update, and reads as manipulative when the content did not actually change. The verdict is that simple. Changing the date to look fresh, with nothing behind it, is not a shortcut to relevance; it is a move Google recognizes and users notice, and it tends to cost the page more than it gains. The date has to track a genuine change, or it should not move at all.
Google has been direct about this. Its search advocates have said that if a page has been substantially changed, refreshing the date makes sense, but artificially freshening one without adding real information does not, and that changing the date while changing nothing else is just noise. The reason it does not work is that Google keeps its own record of when a URL was discovered and when its content actually shifted, and compares that against the date you publish. Faking freshness is an old trick the system already handles; when the claimed date conflicts with what Google observed, it may decline to show a date at all, and sites that churn dates without real updates tend to stall or slide rather than gain.
There is a trust cost on top of the ranking one. A visitor who clicks something stamped today and finds years-old information loses confidence in the source, and that shows up as weaker engagement, which is its own quiet drag. The date is a promise about the content, and breaking it is noticed on both sides.
So the editor changes the date only when the content genuinely changed, treating the timestamp as a record of real revision rather than a lever to pull, and leaving it alone when the update is cosmetic.