I created mw:Extension:InterwikiExistence, which imports a file of Wikipedia page titles and then polls the Wikipedia API to keep the local list of Wikipedia's pages up to date. But it helps if it knows what timestamp to start its polling at. Specifically, system administrators installing the extension need to know the date/time at which the AllPages snapshot gzipped as enwiki-latest-all-titles.gz was generated; that way, the API poll function can begin with the right value in the rcstart (recentchanges) and lestart (logevents) parameters.

Can system administrators rely on the "Last Modified" date/time of the file as that snapshot date/time? Or is a better date/time to use listed somewhere else? Thanks.