Post replies' dates getting mixed up

Ok so I noticed this a while ago but thought it was just my browser messing up, so I ignored it. It’s been seen again so here’s my report on it:

For some reason recently I have been seeing old posts that have new replies getting the dates mixed up (see below), and it has messed up in a way that sometimes I see people’s posts from months ago answering questions posted this week, for example, below is a snip of a conversation between alex_bowen and g33kteacher, and it seems that g33kteacher posted their reply a day ago, but Alex replied in November!

Browser: Chrome version 51.0.2704.84 m
OS: Windows 10 Enterprise 64-Bit


Could you post in the link of the topic

That topic is doing that because, yesterday, I moved all the “PHP is broken” messages that I could find over to that topic.