#!/usr/bin/python3
## The half moon is setting. What's the angle of the perpendicular of
## the terminator, with the horizon of me, the observer?
## In winter, almost flat...
## Copyright       : https://www.gnu.org/licenses/gpl.html
## Author          : https://www.jidanni.org/
## Created On      : Fri May 21 01:53:38 2021
## Last Modified By: Dan Jacobson
## Last Modified On: Fri May 21 03:17:22 2021
## Update Count    : 28
# /usr/lib/python3/dist-packages/ephem/doc/quick.rst
import ephem, math

p = ephem.Observer()
p.lon, p.lat = "120.86617", "24.18169"
p.date = ephem.now()
date2 = p.date + 365 * 11
sun = ephem.Sun()
while p.date <= date2:
    p.date = ephem.next_first_quarter_moon(p.date)
    p.date = p.next_setting(ephem.Moon())
    sun.compute(p)
    print("%2.0f %.19s" % ((sun.alt * 180 / math.pi) + 90, ephem.localtime(p.date)))

# Related?:
# https://en.wikipedia.org/wiki/Terminator_(solar)#Lunar_terminator_illusion