The zomb-eh periodic re-queue branch in GetPosts had no lower bound on
the post's original PostDate -- it re-queued every already-collected
zomb-eh post past the 3-day cooldown, regardless of age.
Add --fromDate <datetime> to bound that branch by PostDate >= the given
date. It stacks with the existing cooldown clause rather than replacing
it, so it applies the same way whether or not --force also drops the
cooldown.