Wikimedia Bugzilla is closed!

The Special:Recentchanges "... starting from ..." link returns a limited number
of rows (N) descending from the current time towards the "from" timestamp.  The
result on a busy wiki is that the newest N rows are shown instead of the oldest
N since the "from" timestamp, which is the same result as when no "from"
parameter is provided.

It looks to me as if the limit query should be ascending from the "from"
timestamp.  The stored results would then need to be reversed to display in
descending time order.