Sunrise also makes it easier to work with little children. The streets are not busy, so they can run around and have fun without getting lost or running into strangers.
On the other hand, if you’re a couple or solo traveler who loves to sleep in, a sunset session might be a better choice. You can explore the city during the day and then start your session in the late afternoon. However, keep in mind that the streets can be busy during this time and finding a good location might be a bit harder.