While this change was in 2014 (T73902), a long ago, such changes may happen any time, and if a change happens after the deployment of DiscussionTools to the affected wiki, even one-day-old comments will be unreplyable. I think this is not okay and should be prepared for in advance; for example, a DiscussionTools configuration parameter could store historical values of the relevant core parameters so that DT could treat strings matching any of these formats signatures.

@matmarex do you have a sense for whether there are any adjustments we can make to the comment parser such that it would recognize timestamps in these cases?

As a least-effort fix, could DiscussionTools always accept UTC timestamps regardless of wiki settings, too?
What about allowing matching "UTC" here and skipping this DST handling code when "UTC" is matched?

The issue description Invitation banner not always desired does not seem to match very well the time zone / signature date format problem discussed, maybe either the title should be improved, or new issue created?

I think the scope of this task is, and has always been, the date format problem, so no new task is needed. The title is indeed a bit vague.

@Tacsipacsi (, @matmarex ) I think that an issue of post signature dates unrecognized (discussion tools timestamp link not made) is unrelated to some invitation banners (not widely known feature).

True… I remembered that there is an old bug report that is more specifically about unrecognized signatures due to dates in old formats, I'll close this as a duplicate of that.