You might not have a lot of time to write, especially if you have a job, be it full time or part time. Or if you're an at-home Mom. Or for any number of reasons, your writing time may be limited.
But even if you can write only an hour a day, or even only an hour a week, treat the time as you would the time you put in at any other job. Don't skip it on a whim. Don't tell yourself you'll put in twice as much time next week to make up for not writing this week.
Sure, there will be sick days and even vacation days. But only when you are *really* sick should you skip your writing time. And schedule vacation days from writing as you would from any other job.
Mark your writing time on the calendar or smartphone or however you keep track of anything important. Because your writing time is important--or at least it should be, if you really want writing to be your career.