When I was younger and dating most sex happened in the evening, after going out together of just getting together after our day was over and naturally wanting to have sex. I was always up for sex the next morning if time allowed, and on weekends, morning sex might even include double sessions.
At the start of every new relationship, throughout my whole life fit into that same pattern ..,. see each other in the evening after school/work, have sex, then morning sex the next day.
As I got older I noticed that we were both tended tired at the end of the day, so sleep was a higher priority than sex. The next morning, waking up after a good night's sleep, I found I was more easily aroused and able to get and maintain great erections with just a little foreplay.
I was never a guy that had morning wood every morning or even most mornings, even when I was younger, but I did notice that it was easier for me to quickly become aroused in the mornings. Do I get horny at other parts of the day? Of course! Seeing a beautiful women, thinking about sex, seeing some of the (straight) pictures and videos here on LPSG, can all get me going.