My year old rooster  crows whenever he wants...lol
sometimes at 1 am, 3:30 am, this morning it was 5:30 am.... when I let him out at 9ish, he jumps out and announces to the world 
" I am on guard watch out"
There was one nite 1 of the older hens ( separate run) went inside and he didn't see her do it, so the crowing started  and didn't stop until I put him inside and he could see her again. 
I am not sure why some cities have rooster by-laws....they are no louder then a barking dog.
and because of these laws , so many rooster chicks are culled.............It just doesn't make sense to me.  Luckily I live in  a small country town that doesn't discriminate against poultry.