If I got two messages saying j was muted for 24 hours would the time stack?
You can be muted for more than 24 hours, but if you got two messages saying that, it's probably just a glitch duplicating the same message.
Furthermore, you couldn't be muted now (or at least not 3 hours ago) because you created this thread and you can't create new threads if muted. Plus, your ongoing threads disappear until you are unmuted; same with your previous posts). They all return when you get unmuted though.