Messaging: timestamp should include days and years in main conversations list

Create a fresh site with some test users Log in (admin is fine) and, via the messaging drawer, send another user a message From the conversation pane, click the arrow at the top left of the drawer to go back to the main conversation list. Verify the datetime next to the conversation is a 24h time format. Something like 14:21 is what we expect. In that conversation, send a few more messages Message another user a couple of times too. Next, check the database and get the ids of the 2 conversations you just created: E.g. select id from mdl_message_conversations; Pick one of the ids and, using the following statement and replacing X, update all the message created times, setting them back a week: update mdl_message_conversations set timecreated = timecreated-604800 where id = X Now, refresh the page and open the messaging pane again. In the private section, verify (you can also confirm the formats match those in the attached screenshot): The first conversation is displayed with a 24h time format. Something like 14:21 is what we expect in terms of format. The second conversation is displayed with a date format, something like dd/mm/YY, e.g. 31/01/2019