Hi all,
my users just reported seeing a “HH” instead of the hours number on the first/last post shortcut, on our discourse instance (https://rembetiko.gr).
Unfortunately, I can’t replicate this on meta. So I suspected it has something to do with the greek localization of the instance. So, I ran a search inside the text customization list. And I searched for “ΗΗ” but using the greek ‘H’ instead of the latin one.
Apparently, in the js.dates.time field, on the HH:mm the HH was substituted with the greek ‘Η’. When I customized it back to the latin character, it started working again 
So maybe this seems like a translation issue.