Star trek Stardate nomenclature?

OK how is stardate arrived at? Is there a zero starting point or is it arbitrary and a relative date with no reference point?
What would September 8 2007 be?

If I recall, stardates had no real reference, they were made up initially just to give a feel that time had passed as Roddenberry had not decided what year Trek happened in, based off the Enterprise layout, the date would just be Sept 8 2007, because I think Stardates began with the founding of the federation,
I found these links via google, perhaps they may help ya

http://www.hillschmidt.de/gbr/sternenzei...

http://www.route56.com/startrek/stardate...

http://www.ussdragonstar.com/utilitycore...

and this one looks promising
http://www.derekbrown.ca/calc/

There's no direct correspondence. See the lengthy article at http://en.wikipedia.org/wiki/Stardate .

i remember someone came up with a correlation to an old earth date, but i cant remember what it was. on a trek rpg i play, we make it the year, the month, the day, and the hour which we post. for example, right now wuold be stardate 2007910.12