gnus: scoring articles by age

[D]

Hi,

as the subject already implies I was wondering if there is a sensible
way to score articles "by age" in gnus.  In principle this functionality
seems to be available via the "Date" key in score files, for example,

 ("Date"
  ("20200430T012905" -1 nil before))

would subtract 1 from the score of any article posted one year ago or
more.  However, you'd have to update that value manually (yuck!) since
you can't put an expression such as

(format-time-string "%+4Y%m%dT%H%M%S" (time-subtract nil 31536000))

into a score file (afaik). As for why would that ever be useful:
consider things like weeding out unsuccessful threads, where any root
that has failed to amass any replies in some fixed time should receive a
negative score, or a root that amassed many replies in a short time
amass a positive score.

Cheers,
D.