The time of day hasn't always been evening as such because circumstances have led to interesting schedules, but if I had a consistently conventional schedule, I'd answer "night."
I've tended to be more physically comfortable doing strenuous or intense things "later in the day" (I don't remember a time when I was different), and I've been more consistent with that habit than, I suppose, if I ever tried to "become a morning person."
(I cheerfully ignore all such propaganda.
) I've also found that the conventional warning about "not being able to sleep after late exercise" doesn't reflect my own experience.
When a number of uncertainties resolve, I'm considering adding something not long after I wake, but it's likely to be light in exertion, "different," and complementary, and I'm unlikely to shift my "main workout" to this timeslot.