Can LUA mods communicate at any time, or do we need specific hooks?

I am working on a LUA mod that runs some external scripts and takes actions when things happen in-game, but the only hook I've seen working so far is when we read from the Hud notifications.

Is there a way with LUA to just execute something every x seconds, or any other general hook we can use? Would I have to run some quest in-game that sends a custom notification every 5s in order to hook in like this?