Run some code an hour before sunrise.

hourtosunrise.py

#!/home/mstucka/bin/python
#Want to do something an hour before sunrise?
#sleep `./hourtosunrise.py`
#./dosomething.sh
import ephem
import datetime
import sys

now=datetime.datetime.now()
Macon=ephem.Observer()
Macon.lat="32.841"
Macon.long="-83.632"
Macon.elevation=116 #meters
sun=ephem.Sun()
sunrise=ephem.localtime(Macon.next_rising(sun))
timetosunrise=(sunrise-now).seconds
sys.stdout.write(str(timetosunrise-3600))