Is it okay to workout twice a day?

So I went to the gym at Thursday night around 8:10pm. I worked out only my back. Got home at 9:40pm and I was gonna go Friday morning around 6:15am and workout legs and arms. Is it okay to do this? Its not over training is it? I will not be sleeping till 6:15am anyway cause i woke up late. BTW im 17 years old weight:174, Height: 6.3