def _calculate_sunrise_hour_angle(self, solar_dec, depression=<NUM_LIT>):
hour_angle_arg = math.degrees(math.acos(<EOL>math.cos(math.radians(<NUM_LIT> + depression)) /<EOL>(math.cos(math.radians(self.latitude)) * math.cos(<EOL>math.radians(solar_dec))) -<EOL>math.tan(math.radians(self.latitude)) *<EOL>math.tan(math.radians(solar_dec))<EOL>))<EOL>return hour_angle_arg<EOL>
Calculate hour angle for sunrise time in degrees.