**Update: Alternative discussed in comments**: show both the Exact and Elapsed at once (for a limited time), as gmail does, and described in T94353#1178467 which includes a list of the configuration used at many other external sites -- (this is Quiddity's recommended option), Then display the Elapsed time in a tooltip, when hovering over the Exact time.
Many users like the new "Elapsed" timestamp e.g. `4 hours ago`
Many users prefer the old "Exact" timestamps. e.g. `16:11, 4 October 2013 (UTC)`
This is especially relevant for anything more than "1 day ago". Anyone trying to closely follow the order of previous posts, has to mouse-over the flow-timestamp in every single post, to see when it occurred.
(Original/alternative idea: This could be added as a user-preference. Possibly, it could be as a checkbox labelled "Use elapsed-timestamps in discussion pages by default" (or similar), under "Date-format" at [[https://www.mediawiki.org/wiki/Special:Preferences#mw-prefsection-rendering |Special:Preferences#mw-prefsection-rendering]].)