I don't know if this has been posted before but I just stumbled upon it, great for setting up specific shots.
It can be set to any location, any date and any time. I did notice that, for the east coast it appears to be off by 3 hours. It shows sunrise as 03:37 when it was actually 06:37. Move the slider to 06:37 and I have the position of sunrise for today. Maybe there's something better our there but this seems to work pretty well.
http://suncalc.net/#/40.7144,-74.006...13.09.19/10:26