Inspiration rarely has anything to do with when I write. Like all of us, I have a busy life: day job, family, sleeping, eating, exercising, etc. I only have an hour or two per day to write, so I write during that time whether or not the muse strikes.
But here's the funny thing about my muse: Once I START writing, she awakens and won't shut up. Starting is the hard part for me; continuing, though, is a breeze.