Writers have habits. Or they don’t, and then feel that if they did stick to a schedule, then the words would come. In the interest of enforcing discipline, routines are probably going to be helpful. That is why so many writers follow them. But hewing to very strict habits every day of one’s life can feel a little too much like work.
Consider the habits of Thomas Hardy (Tess of the d’Ubervilles), described in the magazine The Writer:
Thomas Hardy prefers the night for working, but finds the use of daytime advisable, as a rule. He follows no plan as to outline, and uses no stimulant excepting tea. His habit is to remove boots or slippers as a preliminary to work. He has no definite hours for writing, and only occasionally works against his will.
Excepting his ill-advised strict adherence to tea, which can be excused by his British heritage, this is all perfectly sensible advice.
Choose whatever time works best for you. And take your shoes off first.