How long does it take for weed to get stale?!

I got some really good skunk weed from a friend And I haven't smoked any of it because I've been trying to get clean to find a job. I haven't smoked since new years actually. But I've had this weed since shortly after new years and I check it every Noe and then. Well today I checked it and it felt more crunchy and dryer than before. And is stale weed ok to smoke? Please only answers to help me out, and really f*ck you if ou tell me it's illegal and I shouldn't do it. If you can help out, that would be awesome!!!