Yeah, why wouldnt it be.
Also I would stay awya from the night protein crap and dont believe everything you hear about how weight gainers will make you fat, most of the cheap ones are full of crap but get one with MCT's and if that gets you fat ill refund you the price for the damn gainer myself.
On the other hand its best to take a weight gainer about an hour to two hours after a meal. Weight gainers are full of slow absorbing protein(casein) and therefore are not appropriate as an after workout shake as they take quite a while to get into the muscle, this is where whey shakes are required.