This is a simple mod that adds time stamps to chat messages.
There are often a lot of new chat messages when you come back from being afk on a server (players wanting to buy something, sell something, and so on).
The problem is that you don't know how old these messages are (they could be posted a few seconds ago but they could also be 1 hour old), so you don't know if you should reply to them or not.
This mod solves this issue by adding time stamps to chat messages, so that you know how old these messages are.
This mod can be installed on both, server and client but installing it only on the client or only on the server works as well.