How does he know it's "Morning"

Now he is quiet,This is my dog Buster,He has several jobs around here such as our buddy,door bell,weatherman (he hates thunder,and always lets us know when a storm is coming)he want stay out doors long when it is hot and when it is raining,he needs a rain coat to go out, I need him a good pair of doggy boots,I hate his wet dirty feet when he comes back in after walking on morning dew then on dirt. He is like a having a child, pretty much helpless on his own. Now if you have not noticed from the picture, Buster is blind,he was born that way,he is a full blooded miniature dachshund long haired as you can see,we think he is beautiful. He is as sweet as any dog could be,loves everyone and every thing. Usually Buster sleeps until about 7:00 every morning,not this morning,he was up at the crack of dawn needing to go do his thing out side,he did that and was ready to go back to sleep,now I can not fall asleep as fast as this dog,I have tried several times---so here I am coffee in hand,have had my shower,checked mail here,took a walk-yes crack of dawn is durn early,yet I wonder how does a blind dog know when it is morning,he does,as well as when it is bed time,Ok folks I am sure this has not been as interesting blog as others you may have read today,but still I ask ---How does he know it is morning? well folks I think I will have another cup of coffee now and get ready for the children and my day here----still waiting on my unveiling of our suprise that was suppose to happen----which now I am thinking is going to turn out to be a long story and a bigger supprise then even we thought-------------that will be another bog all together---------good day folks