Can be seen by hovering on .flow-timestamp-ago elements.
@Base: Anyone else is very welcome to provide patches to fix this issue. See https://www.mediawiki.org/wiki/How_to_become_a_MediaWiki_hacker .
(For general info on priorities, see https://www.mediawiki.org/wiki/Bug_management/Development_prioritization .) Also see T178487 for the bigger problem.
Anyone else is very welcome to provide patches
Given stuff like T118024 and T175554 which are quite critical copyright and privacy issues, while this task is merely a big nuisance, the proper fix currently in my opinion is to undeploy, but unfortunately I only know how to do it on an individual private wiki, so I am unable to prepare a patch.