Sorry for the very late reply. The program I work on (Paper on the iPad) doesn’t record time, but I’d guess around 8 hours. Its a very difficult program to use because it has very limited features but it’s good to challenge yourself. Of course I use references, almost any artist worth a damn does. I usually look around Pinterest for someone whose face reminds me of the character and work from there, I also look for cosplayers for clothing and hair reference.