Most crossbow manufacturers assure that you can keep your crossbow cocked for an entire day of hunting, but warn that you should de-cock or discharge it afterward. Some recommend giving it a "rest" every 4 hours for about half an hour.
And all agree that in no circumstance you should leave it cocked for more than 24 hours as it would stretch and wear out prematurely the strings and the cables. The prolonged pressure could affect negatively the limbs as well.
So in a nutshell, the answer is:
Apparently, the less time it stays cocked, the longer it would serve you before having to replace components or repair it.
A main advantage of crossbows over bows is that there is no need to hold back its draw weight in order to aim and shoot. Once loaded, the hunter can have it ready to shoot for hours. Which allows them to focus on observing and taking the time to prepare for the perfect shot.
Cocking a crossbow takes physical effort and time so it is understandable that most people would prefer if they could keep it cocked until an opportunity for a shot arises. Whenever that happens.
It is tempting, isn't it?
Many hunters claim on various online platforms that they've left their crossbows cocked for as long as a week or even more... and didn't notice any losses in performance.
That might be true, but the manufacturers actually warn about damage accumulation over time - result from putting unnecessary strain on the weapon components.
But how to proceed if at the end of the hunt there is still an arrow loaded in your crossbow? Should you just fire it into the ground?
Most times - not a good idea. The chances to damage the arrow are too high.
And what about removing the arrow and "dry firing" to release the string?
All crossbow makers warn against that as it has a very high potential of damaging the crossbow. Some models even incorporate a Dry Fire Inhibitor (DFI) mechanism that prevents firing in the absence of an arrow in the flight groove.
There are at least a couple of ways to do that:
The simplest and most obvious approach is to shoot a field point arrow into a regular target.
And then there are some products that are made specifically to deal with the situation.
These are durable arrows that you replace your hunting arrow with before shooting into the ground. Still, you'd need to pick a spot with softer ground and no rocks as it could ricochet.
These are small and portable targets that can't be penetrated by the arrow, so you can aim and shoot at it from a close distance. If the crossbow is loaded with a hunting arrow with some sort of broadhead, it is recommended to replace it with an arrow with a field point tip before doing so.
Aside from these products that can be used by any crossbow, some late models even come with built-in devices to make loading and unloading them easy for the user - TenPoint's ACUslide system, for example:
Now you might be thinking...
Well, can you? I guess you could do that if it's a crossbow model with lower-ish draw weight and no Anti-Dry-Fire feature, but this is generally not a good idea and not worth the risk of hurting yourself.