Don't know why this would be a problem with htmx in particular; I'd expect this to work like with every other site, by using moment.js and a JS timer event chan

Don't know why this would be a problem with htmx in particular; I'd expect this to work like with every other site, by using moment.js and a JS timer event changing date text into a relative date/time. Not a good practice to send "now" or other indeterministic data as string in a server-rendered page anyway, and I wouldn't expect anyone to do it like that (well, except for fingerprinting or sth). Though I don't even know if it's possible to tunnel your own JS through hmtx pages after all tbh. If not, that would be a problem/a no go from my PoV as I see absolutely no reason to add (or subtract, for that matter) syntax constructs to/from HTML when SGML has plenty, and in fact can already describe adding or replacing fragments at a purely syntactical level without mixing in opinionated "semantics".