This is one of those things which is very easy for a human to pick out, but more difficult to automate and scale. It is the reason why this functionality since/before is on the operators page but not in a UI element.
This is correct, the date of a page is when it first entered into the index.
This should improve along with crawling more, and we’re aware of it, but it’s a case of where to allocate effort. We’re aware of it and returning every now and again to thinking about ways it could be improved.
So:
- intentional
- limitations
- the dates are all going to be last crawled/modified, so there would be no two steps to this process, there is only one date to offer, the text in Operators says:
to restrict results to those that were last modified since then
which I guess could be better as
to restrict results to those that were last modified since then (in cases where a page has not been modified this will be the date we found the page)
to cut out some confusion.