Gen 2:3 So God blessed the seventh day and made it holy, because on it God rested from all his work that he had done in creation.
-this is the first time God blessed something and called it holy. note-worthy.
-the Almighty rested!
-again, it's all about God.
hey, this is the first holiday! (holy day) so that's where they got the idea of declaring holidays...i knew all things good come from God! here is further proof

personally, i never understood what's the big deal about holidays. why would an important person/occasion be a reason for not going to work or school? i think it would be more meaningful to celebrate the ___ day where you work (except for Christmas ad new years) but you won't hear me complain if i get to rest for a day!
but still, to honor God by not doing anything? there must be a really good reason for that. here are some reasons i've come up with:
-we are designed to need rest so God is teaching us its importance so we can live a good life
-we stop regular work so we can spend time with Him and remember what He's done
-we appreciate our work more when we get rest once in a while
-God is emphasizing that we need to work more than we are to rest. 7:1