There is a theory that the brain is more creative in the morning, especially in your waking moments. For this reason, many writers keep their notepad by their beds and make sure that the very first thing they do when they open their eyes each morning, is write. The resultant notes are called “morning pages”.
Morning pages might contain what a writer remembers of their dreams or perhaps the writer will jot down the very first words that come to mind – however nonsensical. Some writers say that this exercise helps them ‘slip’ more easily into what writers’ call the “writing rapture” when a writer feels ideas are pouring into their mind. When writers write in the morning, so the theory goes, they are closer to their sleeping state and the mind is more imaginative and/or receptive to ideas.
Nontheless, there are plenty of writers who write late at night – for the same reason that they say the closer to sleep they are, the more creative their ideas. Then there are other writers who find their most productive hours are in the middle of the day (the Harry Potter author, J.K. Rowling is a good example. She wrote her first book in a busy Edinburgh café).
Therefore, it is clear that different times of the day work for different people and it is really of no consequence whether you are a morning, day or night writer. What is important is that you write and that you find your ideal writing time. Experiment and find what works for you and then set an hour aside each day at that time and write, but do write.