if you look real close at the time of sunset and rise,you can't see past or brfore that time anyway.
1/2 hr. after sunset is dark.you have to go by the book time of sunset.watch the news in the evenings and it will give you the time of sunset,then watch the darkness and it is pretty close.it is close enough that you can't see anything well enough to tell what it is ; man or beast.([X(])
JMHO.
