Obviously you can man. Yes, just set up your sell or buy orders and do your work. The trade will automatically happen accordingly. You can even set up a trading bot as well. So learn about indications, choose the best coin on a best exchange which will have high trading volume. These are more important than the time you allot. You need watch out the market more when either you wish to buy or sell. Once you place the order, just relax and do your other work. So time is not a matter. Its wise versa.