Absolutely. You have to be disciplined if you hope to write for a living. Treating your writing like a regular day job is a good way to approach it, even if you already have a day job and write at night. I worked full time at a computer software company and wrote during the evenings and on the weekends. Then I worked part time for a while. It took about five years of being steadily published before I was comfortable enough to do it full time. Oddly enough, when you have more time to do it, you still feel as though you never catch up. I still get up early, early for me, anyway, and get to work by 9 am. The only time the television goes on is when I break for lunch. Television is a huge temptation, except for the music-only channels.