A lot of creative writing blogs, courses and books recommend that you write every day. Do just a few hundred words every morning or evening at the same time.It seems to be everywhere: little and often is the best way to keep your writing going, they say. Don't worry about doing a big block when you can do small chunks frequently. It seems to make sense - keep the creative process going, or whatever.
But this is rubbish if you're not a full-time writer. Most of us who have jobs spend daytimes thinking of other things apart from writing. Not only do we have no time to write but we also have no time to think about the writing. No opportunity to get immersed in it. Full-time writers face procrastination as their greatest enemy but for the rest of us it is day to day life. Different problem, different solution.
So, the answer is a decent sized wad of time: a block of hours cleared of other stuff when you can sit and think about your writing and get back into it. The few hundred words a day thing never works because you'll just pick up your old stuff, mess around and tinker a little. Not move on.
How do I know this? Because I've tried to the textbook way with my novels and what happens is I get stuck. It's Groundhog Day every time. Start on the same page. Read back. Remind myself of what is going on. Change one word. Check spelling. Time's up!
What I actually need is hours and hours immeresed in writing: drawn into the novel to go backwards a little bit and then push forward. Get back into the plot and see where it all is going. Even if you have notes it's easy to get mixed up you have to shake off all your day-to-day work stuff that sitting in your head.
Forget writing every day and instead make a weekly or monthly target. Go part time from the day job and stop watching the telly. Make those blocks.