It shouldn't harm it as long as it doesn't overheat or as long as there's no stability issues. I personally wouldn't do it but there are people who leave their PC's on 24/7 and they still last for years. Just make sure you don't block the intake our exhaust vents, and don't close the laptop lid. At the very least let it restart every 24 hours in case there are windows updates or some instability in any applications. Also don't leave it on a soft surface that might hinder the air flow.
There are some computers that are simply left on all the time with only restarts, like office PCs and home servers. I have a home server made out of bay trail laptop components and it never shuts off unless there's a power failure. The only reason I recommend caution with the laptop is because it's a gaming machine and they are usually the first to overheat if air flow problems arise.