There are two things involved here;
1. You main job
2. Trading(passive income).

The former should be considered more important than the later. So you would try as much as possible not to let the later affect the former.
Apart from day trading you can also be trading intermittently. For example, when all coins are red you buy some coins of your choice according to your research and wait for someday or week when the whole market will move and cash out. I follow this up and make some gains.
Try make trading not to be time consuming so that it won't affect your job