According to this article on CNN, A Time to Kill received 15 rejections before it was finally accepted by a publisher. In the interview, Grisham reveals that in the beginning his writing day started at 5:30 a.m. and ended after he finished writing one page.
I've been struggling to prioritize time to write these past few weeks and have often thought about purchasing an egg timer and using it as a writing prompt. If I write 30 minutes per day to start, I'd finish a page every couple of days. It's not much, but as I've discovered...it's the consistency that is important.