Before you read any further, I should dispel any preconceived notion that there is one perfect time for everyone to write. There is no magical witching hour where the words fit together better than any other time, and no special planetary alignment that makes your metaphors spring to life. If you were hoping for that, you will be sadly disappointed. However, we can develop the best time for our own writing process, and after reinforcing it for a while, it does have an effect on our writing which can seem, at times, magical.
I usually respond in a very polite manner that you don't find time to write, you make time to write. Splitting hairs? Not really. Anything we want to pursue we should be willing to prioritize above something else that we do. Admittedly, we have to place top priority on things like our job, our family, etc. However, if we really want to be a writer as well, we need to push around some things and make that special half-hour or so a day when we can commit to the keyboard or notebook and write.
Usually at this point I make reference to best-selling author Mary Kubica. (I often refer to her because we had a humorous meeting during a book signing, but that's another story.) Anyway, she wrote her first novel while taking care of her newborn. That's worth repeating: while taking care of her newborn! She had a story she wanted to write, and a newborn who was clearly her top priority. So how did she write anything, much less her first novel, The Good Girl? She made time. She really wanted to write the story, so she would wake up a half-hour earlier than usual every morning and write until the newborn child woke up, then be a parent. Difficult? Obviously. However, she wanted it that much, and the success of her career since then is testimony to the importance of making time.
The other thing I did promise with this post is about how time can affect your writing. The most interesting thing that happens when you start writing at a regular time (and possibly in the same place) is that you start to condition yourself. When writing time comes around and you settle in for that period of creation, your mind starts preparing itself for the process. The more you do regular writing at a fixed time, the more your mind thinks, "Ah - time to do the writing thing" and the creative juices start flowing. Eventually, you are like Pavlov's dog, anticipating the opportunity to be creative and mentally preparing before you've even started.
It might sound crass to suggest we are trainable like dogs, but our mind very much trains itself through repetition. And if we do this, we do, in fact, create a sort of witching hour where our creativity will peak, our metaphors will spring to life, and the things we create will feel, in fact, magical.