Displaying only the day of the week and not the complete date doesn't make sense for older messages. Looking at the screenshot below, you'd think that the "Wednesday 9:52pm" message was sent yesterday, but it's actually months old. If a post is older than 1 week, it should display the date instead. "9/21/2016 9:52pm" makes much more sense in this context.
Customer support service by UserEcho