def test_daylight_saving():
"""Test the applicaiton of daylight saving time."""
nyc = Location('New_York', country='USA', latitude=40.72, longitude=-74.02,
time_zone=-5)
daylight_saving = AnalysisPeriod(st_month=3, st_day=8, st_hour=2,
end_month=11, end_day=1, end_hour=2)
sp = Sunpath.from_location(nyc, daylight_saving_period=daylight_saving)
dt1 = DateTime(6, 21, 12, 0)
dt2 = DateTime(12, 21, 12, 0)
dt3 = DateTime(6, 21, 0)
dt4 = DateTime(12, 21, 0)
assert sp.is_daylight_saving_hour(dt1)
assert not sp.is_daylight_saving_hour(dt2)
assert sp.is_daylight_saving_hour(dt3)
assert not sp.is_daylight_saving_hour(dt4)
sun1ds = sp.calculate_sun_from_date_time(dt1)
sun2ds = sp.calculate_sun_from_date_time(dt2)
sun3ds = sp.calculate_sun_from_date_time(dt3)
sun4ds = sp.calculate_sun_from_date_time(dt4)
sp.daylight_saving_period = None
assert sun1ds != sp.calculate_sun_from_date_time(dt1)
assert sun3ds != sp.calculate_sun_from_date_time(dt3)
assert sun1ds.altitude == \
approx(sp.calculate_sun_from_date_time(dt1.sub_hour(1)).altitude, rel=1e-2)
assert sun3ds.altitude == \
approx(sp.calculate_sun_from_date_time(dt3.sub_hour(1)).altitude, rel=1e-2)
sun2 = sp.calculate_sun_from_date_time(dt2)
sun4 = sp.calculate_sun_from_date_time(dt4)
assert sun2 == sun2ds
assert sun4 == sun4ds
def test_date_time_add_sub():
"""Test the add and subtract methods for DateTime."""
dt1 = DateTime(6, 21, 12)
dt2 = dt1.add_hour(1)
dt3 = dt1.sub_hour(1)
dt4 = dt1.add_minute(1)
dt5 = dt1.sub_minute(1)
assert dt2 == DateTime(6, 21, 13)
assert dt3 == DateTime(6, 21, 11)
assert dt4 == DateTime(6, 21, 12, 1)
assert dt5 == DateTime(6, 21, 11, 59)
