It may well be the chinese, 20+century BC, but then too, other prehistorical cultures did study the positions of the Sun and stars.

There's a timeline which starts with the first eclipse record (1223 BC) at

http://www.hao.ucar.edu/e...tion/spTimeline.php,

and additionnal discussion on that site.

Short answer: I don't know the answer, but maybe some of the sites I've listed can bring you to it.