Current File : //data/old/usr/local/lib/python3.6/site-packages/astral/sun.py
import datetime
from math import (
acos,
asin,
atan2,
cos,
degrees,
fabs,
floor,
radians,
sin,
sqrt,
tan,
)
from typing import Dict, Optional, Tuple, Union
import pytz
from astral import Depression, Observer, SunDirection, now, today
__all__ = [
"sun",
"dawn",
"sunrise",
"noon",
"midnight",
"sunset",
"dusk",
"daylight",
"night",
"twilight",
"blue_hour",
"golden_hour",
"rahukaalam",
"zenith",
"azimuth",
"elevation",
"time_at_elevation",
]
# Using 32 arc minutes as sun's apparent diameter
SUN_APPARENT_RADIUS = 32.0 / (60.0 * 2.0)
def julianday(date: datetime.date) -> float:
"""Calculate the Julian Day for the specified date"""
y = date.year
m = date.month
d = date.day
if m <= 2:
y -= 1
m += 12
a = floor(y / 100)
b = 2 - a + floor(a / 4)
jd = floor(365.25 * (y + 4716)) + floor(30.6001 * (m + 1)) + d + b - 1524.5
return jd
def minutes_to_timedelta(minutes: float) -> datetime.timedelta:
"""Convert a floating point number of minutes to a :class:`~datetime.timedelta`"""
d = int(minutes / 1440)
minutes = minutes - (d * 1440)
minutes = minutes * 60
s = int(minutes)
sfrac = minutes - s
us = int(sfrac * 1_000_000)
return datetime.timedelta(days=d, seconds=s, microseconds=us)
def jday_to_jcentury(julianday: float) -> float:
"""Convert a Julian Day number to a Julian Century"""
return (julianday - 2451545.0) / 36525.0
def jcentury_to_jday(juliancentury: float) -> float:
"""Convert a Julian Century number to a Julian Day"""
return (juliancentury * 36525.0) + 2451545.0
def geom_mean_long_sun(juliancentury: float) -> float:
"""Calculate the geometric mean longitude of the sun"""
l0 = 280.46646 + juliancentury * (36000.76983 + 0.0003032 * juliancentury)
return l0 % 360.0
def geom_mean_anomaly_sun(juliancentury: float) -> float:
"""Calculate the geometric mean anomaly of the sun"""
return 357.52911 + juliancentury * (35999.05029 - 0.0001537 * juliancentury)
def eccentric_location_earth_orbit(juliancentury: float) -> float:
"""Calculate the eccentricity of Earth's orbit"""
return 0.016708634 - juliancentury * (0.000042037 + 0.0000001267 * juliancentury)
def sun_eq_of_center(juliancentury: float) -> float:
"""Calculate the equation of the center of the sun"""
m = geom_mean_anomaly_sun(juliancentury)
mrad = radians(m)
sinm = sin(mrad)
sin2m = sin(mrad + mrad)
sin3m = sin(mrad + mrad + mrad)
c = (
sinm * (1.914602 - juliancentury * (0.004817 + 0.000014 * juliancentury))
+ sin2m * (0.019993 - 0.000101 * juliancentury)
+ sin3m * 0.000289
)
return c
def sun_true_long(juliancentury: float) -> float:
"""Calculate the sun's true longitude"""
l0 = geom_mean_long_sun(juliancentury)
c = sun_eq_of_center(juliancentury)
return l0 + c
def sun_true_anomoly(juliancentury: float) -> float:
"""Calculate the sun's true anomaly"""
m = geom_mean_anomaly_sun(juliancentury)
c = sun_eq_of_center(juliancentury)
return m + c
def sun_rad_vector(juliancentury: float) -> float:
v = sun_true_anomoly(juliancentury)
e = eccentric_location_earth_orbit(juliancentury)
return (1.000001018 * (1 - e * e)) / (1 + e * cos(radians(v)))
def sun_apparent_long(juliancentury: float) -> float:
true_long = sun_true_long(juliancentury)
omega = 125.04 - 1934.136 * juliancentury
return true_long - 0.00569 - 0.00478 * sin(radians(omega))
def mean_obliquity_of_ecliptic(juliancentury: float) -> float:
seconds = 21.448 - juliancentury * (
46.815 + juliancentury * (0.00059 - juliancentury * (0.001813))
)
return 23.0 + (26.0 + (seconds / 60.0)) / 60.0
def obliquity_correction(juliancentury: float) -> float:
e0 = mean_obliquity_of_ecliptic(juliancentury)
omega = 125.04 - 1934.136 * juliancentury
return e0 + 0.00256 * cos(radians(omega))
def sun_rt_ascension(juliancentury: float) -> float:
"""Calculate the sun's right ascension"""
oc = obliquity_correction(juliancentury)
al = sun_apparent_long(juliancentury)
tananum = cos(radians(oc)) * sin(radians(al))
tanadenom = cos(radians(al))
return degrees(atan2(tananum, tanadenom))
def sun_declination(juliancentury: float) -> float:
"""Calculate the sun's declination"""
e = obliquity_correction(juliancentury)
lambd = sun_apparent_long(juliancentury)
sint = sin(radians(e)) * sin(radians(lambd))
return degrees(asin(sint))
def var_y(juliancentury: float) -> float:
epsilon = obliquity_correction(juliancentury)
y = tan(radians(epsilon) / 2.0)
return y * y
def eq_of_time(juliancentury: float) -> float:
l0 = geom_mean_long_sun(juliancentury)
e = eccentric_location_earth_orbit(juliancentury)
m = geom_mean_anomaly_sun(juliancentury)
y = var_y(juliancentury)
sin2l0 = sin(2.0 * radians(l0))
sinm = sin(radians(m))
cos2l0 = cos(2.0 * radians(l0))
sin4l0 = sin(4.0 * radians(l0))
sin2m = sin(2.0 * radians(m))
Etime = (
y * sin2l0
- 2.0 * e * sinm
+ 4.0 * e * y * sinm * cos2l0
- 0.5 * y * y * sin4l0
- 1.25 * e * e * sin2m
)
return degrees(Etime) * 4.0
def hour_angle(
latitude: float, declination: float, zenith: float, direction: SunDirection
) -> float:
"""Calculate the hour angle of the sun
See https://en.wikipedia.org/wiki/Hour_angle#Solar_hour_angle
Args:
latitude: The latitude of the obersver
declination: The declination of the sun
zenith: The zenith angle of the sun
direction: The direction of traversal of the sun
Raises:
ValueError
"""
latitude_rad = radians(latitude)
declination_rad = radians(declination)
zenith_rad = radians(zenith)
# n = cos(zenith_rad)
# d = cos(latitude_rad) * cos(declination_rad)
# t = tan(latitude_rad) * tan(declination_rad)
# h = (n / d) - t
h = (cos(zenith_rad) - sin(latitude_rad) * sin(declination_rad)) / (
cos(latitude_rad) * cos(declination_rad)
)
HA = acos(h)
if direction == SunDirection.SETTING:
HA = -HA
return HA
def adjust_to_horizon(elevation: float) -> float:
"""Calculate the extra degrees of depression that you can see round the earth
due to the increase in elevation.
Args:
elevation: Elevation above the earth in metres
Returns:
A number of degrees to add to adjust for the elevation of the observer
"""
if elevation <= 0:
return 0
r = 6356900 # radius of the earth
a1 = r
h1 = r + elevation
theta1 = acos(a1 / h1)
return degrees(theta1)
def adjust_to_obscuring_feature(elevation: Tuple[float, float]) -> float:
"""Calculate the number of degrees to adjust for an obscuring feature"""
if elevation[0] == 0.0:
return 0.0
sign = -1 if elevation[0] < 0.0 else 1
return sign * degrees(
acos(fabs(elevation[0]) / sqrt(pow(elevation[0], 2) + pow(elevation[1], 2)))
)
def refraction_at_zenith(zenith: float) -> float:
"""Calculate the degrees of refraction of the sun due to the sun's elevation."""
elevation = 90 - zenith
if elevation >= 85.0:
return 0
refractionCorrection = 0.0
te = tan(radians(elevation))
if elevation > 5.0:
refractionCorrection = (
58.1 / te - 0.07 / (te * te * te) + 0.000086 / (te * te * te * te * te)
)
elif elevation > -0.575:
step1 = -12.79 + elevation * 0.711
step2 = 103.4 + elevation * step1
step3 = -518.2 + elevation * step2
refractionCorrection = 1735.0 + elevation * step3
else:
refractionCorrection = -20.774 / te
refractionCorrection = refractionCorrection / 3600.0
return refractionCorrection
def time_of_transit(
observer: Observer, date: datetime.date, zenith: float, direction: SunDirection
) -> datetime.datetime:
"""Calculate the time in the UTC timezone when the sun transits the specificed zenith
Args:
observer: An observer viewing the sun at a specific, latitude, longitude and elevation
date: The date to calculate for
zenith: The zenith angle for which to calculate the transit time
direction: The direction that the sun is traversing
Raises:
ValueError if the zenith is not transitted by the sun
Returns:
the time when the sun transits the specificed zenith
"""
if observer.latitude > 89.8:
latitude = 89.8
elif observer.latitude < -89.8:
latitude = -89.8
else:
latitude = observer.latitude
adjustment_for_elevation = 0.0
if isinstance(observer.elevation, float) and observer.elevation > 0.0:
adjustment_for_elevation = adjust_to_horizon(observer.elevation)
elif isinstance(observer.elevation, tuple):
adjustment_for_elevation = adjust_to_obscuring_feature(observer.elevation)
adjustment_for_refraction = refraction_at_zenith(zenith + adjustment_for_elevation)
jd = julianday(date)
t = jday_to_jcentury(jd)
solarDec = sun_declination(t)
hourangle = hour_angle(
latitude,
solarDec,
zenith + adjustment_for_elevation - adjustment_for_refraction,
direction,
)
delta = -observer.longitude - degrees(hourangle)
timeDiff = 4.0 * delta
timeUTC = 720.0 + timeDiff - eq_of_time(t)
t = jday_to_jcentury(jcentury_to_jday(t) + timeUTC / 1440.0)
solarDec = sun_declination(t)
hourangle = hour_angle(
latitude,
solarDec,
zenith + adjustment_for_elevation + adjustment_for_refraction,
direction,
)
delta = -observer.longitude - degrees(hourangle)
timeDiff = 4.0 * delta
timeUTC = 720 + timeDiff - eq_of_time(t)
td = minutes_to_timedelta(timeUTC)
dt = datetime.datetime(date.year, date.month, date.day) + td
dt = pytz.utc.localize(dt) # pylint: disable=E1120
return dt
def time_at_elevation(
observer: Observer,
elevation: float,
date: Optional[datetime.date] = None,
direction: SunDirection = SunDirection.RISING,
tzinfo: Union[str, datetime.tzinfo] = pytz.utc,
) -> datetime.datetime:
"""Calculates the time when the sun is at the specified elevation on the specified date.
Note:
This method uses positive elevations for those above the horizon.
Elevations greater than 90 degrees are converted to a setting sun
i.e. an elevation of 110 will calculate a setting sun at 70 degrees.
Args:
elevation: Elevation of the sun in degrees above the horizon to calculate for.
observer: Observer to calculate for
date: Date to calculate for. Default is today's date in the timezone `tzinfo`.
direction: Determines whether the calculated time is for the sun rising or setting.
Use ``SunDirection.RISING`` or ``SunDirection.SETTING``. Default is rising.
tzinfo: Timezone to return times in. Default is UTC.
Returns:
Date and time at which the sun is at the specified elevation.
"""
if elevation > 90.0:
elevation = 180.0 - elevation
direction = SunDirection.SETTING
if isinstance(tzinfo, str):
tzinfo = pytz.timezone(tzinfo)
if date is None:
date = today(tzinfo)
zenith = 90 - elevation
try:
return time_of_transit(observer, date, zenith, direction).astimezone(tzinfo)
except ValueError as exc:
if exc.args[0] == "math domain error":
raise ValueError(
f"Sun never reaches an elevation of {elevation} degrees "
"at this location."
) from exc
else:
raise
def noon(
observer: Observer,
date: Optional[datetime.date] = None,
tzinfo: Union[str, datetime.tzinfo] = pytz.utc,
) -> datetime.datetime:
"""Calculate solar noon time when the sun is at its highest point.
Args:
observer: An observer viewing the sun at a specific, latitude, longitude and elevation
date: Date to calculate for. Default is today for the specified tzinfo.
tzinfo: Timezone to return times in. Default is UTC.
Returns:
Date and time at which noon occurs.
"""
if isinstance(tzinfo, str):
tzinfo = pytz.timezone(tzinfo)
if date is None:
date = today(tzinfo)
jc = jday_to_jcentury(julianday(date))
eqtime = eq_of_time(jc)
timeUTC = (720.0 - (4 * observer.longitude) - eqtime) / 60.0
hour = int(timeUTC)
minute = int((timeUTC - hour) * 60)
second = int((((timeUTC - hour) * 60) - minute) * 60)
if second > 59:
second -= 60
minute += 1
elif second < 0:
second += 60
minute -= 1
if minute > 59:
minute -= 60
hour += 1
elif minute < 0:
minute += 60
hour -= 1
if hour > 23:
hour -= 24
date += datetime.timedelta(days=1)
elif hour < 0:
hour += 24
date -= datetime.timedelta(days=1)
noon = datetime.datetime(date.year, date.month, date.day, hour, minute, second)
return pytz.utc.localize(noon).astimezone(tzinfo) # pylint: disable=E1120
def midnight(
observer: Observer,
date: Optional[datetime.date] = None,
tzinfo: Union[str, datetime.tzinfo] = pytz.utc,
) -> datetime.datetime:
"""Calculate solar midnight time.
Note:
This calculates the solar midnight that is closest
to 00:00:00 of the specified date i.e. it may return a time that is on
the previous day.
Args:
observer: An observer viewing the sun at a specific, latitude, longitude and elevation
date: Date to calculate for. Default is today for the specified tzinfo.
tzinfo: Timezone to return times in. Default is UTC.
Returns:
Date and time at which midnight occurs.
"""
if isinstance(tzinfo, str):
tzinfo = pytz.timezone(tzinfo)
if date is None:
date = today(tzinfo)
jd = julianday(date)
newt = jday_to_jcentury(jd + 0.5 + -observer.longitude / 360.0)
eqtime = eq_of_time(newt)
timeUTC = (-observer.longitude * 4.0) - eqtime
timeUTC = timeUTC / 60.0
hour = int(timeUTC)
minute = int((timeUTC - hour) * 60)
second = int((((timeUTC - hour) * 60) - minute) * 60)
if second > 59:
second -= 60
minute += 1
elif second < 0:
second += 60
minute -= 1
if minute > 59:
minute -= 60
hour += 1
elif minute < 0:
minute += 60
hour -= 1
if hour < 0:
hour += 24
date -= datetime.timedelta(days=1)
midnight = datetime.datetime(date.year, date.month, date.day, hour, minute, second)
return pytz.utc.localize(midnight).astimezone(tzinfo) # pylint: disable=E1120
def zenith_and_azimuth(
observer: Observer, dateandtime: datetime.datetime, with_refraction: bool = True,
) -> Tuple[float, float]:
if observer.latitude > 89.8:
latitude = 89.8
elif observer.latitude < -89.8:
latitude = -89.8
else:
latitude = observer.latitude
longitude = observer.longitude
if dateandtime.tzinfo is None:
zone = 0.0
utc_datetime = dateandtime
else:
zone = -dateandtime.utcoffset().total_seconds() / 3600.0 # type: ignore
utc_datetime = dateandtime.astimezone(pytz.utc)
timenow = (
utc_datetime.hour
+ (utc_datetime.minute / 60.0)
+ (utc_datetime.second / 3600.0)
)
JD = julianday(dateandtime)
t = jday_to_jcentury(JD + timenow / 24.0)
solarDec = sun_declination(t)
eqtime = eq_of_time(t)
solarTimeFix = eqtime - (4.0 * -longitude) + (60 * zone)
trueSolarTime = (
dateandtime.hour * 60.0
+ dateandtime.minute
+ dateandtime.second / 60.0
+ solarTimeFix
)
# in minutes as a float, fractional part is seconds
while trueSolarTime > 1440:
trueSolarTime = trueSolarTime - 1440
hourangle = trueSolarTime / 4.0 - 180.0
# Thanks to Louis Schwarzmayr for the next line:
if hourangle < -180:
hourangle = hourangle + 360.0
harad = radians(hourangle)
csz = sin(radians(latitude)) * sin(radians(solarDec)) + cos(
radians(latitude)
) * cos(radians(solarDec)) * cos(harad)
if csz > 1.0:
csz = 1.0
elif csz < -1.0:
csz = -1.0
zenith = degrees(acos(csz))
azDenom = cos(radians(latitude)) * sin(radians(zenith))
if abs(azDenom) > 0.001:
azRad = (
(sin(radians(latitude)) * cos(radians(zenith))) - sin(radians(solarDec))
) / azDenom
if abs(azRad) > 1.0:
if azRad < 0:
azRad = -1.0
else:
azRad = 1.0
azimuth = 180.0 - degrees(acos(azRad))
if hourangle > 0.0:
azimuth = -azimuth
else:
if latitude > 0.0:
azimuth = 180.0
else:
azimuth = 0.0
if azimuth < 0.0:
azimuth = azimuth + 360.0
if with_refraction:
zenith -= refraction_at_zenith(zenith)
return zenith, azimuth
def zenith(
observer: Observer,
dateandtime: Optional[datetime.datetime] = None,
with_refraction: bool = True,
) -> float:
"""Calculate the zenith angle of the sun.
Args:
observer: Observer to calculate the solar zenith for
dateandtime: The date and time for which to calculate the angle.
If `dateandtime` is None or is a naive Python datetime
then it is assumed to be in the UTC timezone.
with_refraction: If True adjust zenith to take refraction into account
Returns:
The zenith angle in degrees.
"""
if dateandtime is None:
dateandtime = now(pytz.UTC)
return zenith_and_azimuth(observer, dateandtime, with_refraction)[0]
def azimuth(
observer: Observer, dateandtime: Optional[datetime.datetime] = None,
) -> float:
"""Calculate the azimuth angle of the sun.
Args:
observer: Observer to calculate the solar azimuth for
dateandtime: The date and time for which to calculate the angle.
If `dateandtime` is None or is a naive Python datetime
then it is assumed to be in the UTC timezone.
Returns:
The azimuth angle in degrees clockwise from North.
If `dateandtime` is a naive Python datetime then it is assumed to be
in the UTC timezone.
"""
if dateandtime is None:
dateandtime = now(pytz.UTC)
return zenith_and_azimuth(observer, dateandtime)[1]
def elevation(
observer: Observer,
dateandtime: Optional[datetime.datetime] = None,
with_refraction: bool = True,
) -> float:
"""Calculate the sun's angle of elevation.
Args:
observer: Observer to calculate the solar elevation for
dateandtime: The date and time for which to calculate the angle.
If `dateandtime` is None or is a naive Python datetime
then it is assumed to be in the UTC timezone.
with_refraction: If True adjust elevation to take refraction into account
Returns:
The elevation angle in degrees above the horizon.
"""
if dateandtime is None:
dateandtime = now(pytz.UTC)
return 90.0 - zenith(observer, dateandtime, with_refraction)
def dawn(
observer: Observer,
date: Optional[datetime.date] = None,
depression: Union[float, Depression] = Depression.CIVIL,
tzinfo: Union[str, datetime.tzinfo] = pytz.utc,
) -> datetime.datetime:
"""Calculate dawn time.
Args:
observer: Observer to calculate dawn for
date: Date to calculate for. Default is today's date in the timezone `tzinfo`.
depression: Number of degrees below the horizon to use to calculate dawn.
Default is for Civil dawn i.e. 6.0
tzinfo: Timezone to return times in. Default is UTC.
Returns:
Date and time at which dawn occurs.
Raises:
ValueError: if dawn does not occur on the specified date
"""
if isinstance(tzinfo, str):
tzinfo = pytz.timezone(tzinfo)
if date is None:
date = today(tzinfo)
dep: float = 0.0
if isinstance(depression, Depression):
dep = depression.value
else:
dep = depression
try:
return time_of_transit(
observer, date, 90.0 + dep, SunDirection.RISING
).astimezone(tzinfo)
except ValueError as exc:
if exc.args[0] == "math domain error":
raise ValueError(
f"Sun never reaches {dep} degrees below the horizon, at this location."
) from exc
else:
raise
def sunrise(
observer: Observer,
date: Optional[datetime.date] = None,
tzinfo: Union[str, datetime.tzinfo] = pytz.utc,
) -> datetime.datetime:
"""Calculate sunrise time.
Args:
observer: Observer to calculate sunrise for
date: Date to calculate for. Default is today's date in the timezone `tzinfo`.
tzinfo: Timezone to return times in. Default is UTC.
Returns:
Date and time at which sunrise occurs.
Raises:
ValueError: if the sun does not reach the horizon on the specified date
"""
if isinstance(tzinfo, str):
tzinfo = pytz.timezone(tzinfo)
if date is None:
date = today(tzinfo)
try:
return time_of_transit(
observer, date, 90.0 + SUN_APPARENT_RADIUS, SunDirection.RISING,
).astimezone(tzinfo)
except ValueError as exc:
if exc.args[0] == "math domain error":
z = zenith(observer, noon(observer, date))
if z > 90.0:
msg = "Sun is always below the horizon on this day, at this location."
else:
msg = "Sun is always above the horizon on this day, at this location."
raise ValueError(msg) from exc
else:
raise
def sunset(
observer: Observer,
date: Optional[datetime.date] = None,
tzinfo: Union[str, datetime.tzinfo] = pytz.utc,
) -> datetime.datetime:
"""Calculate sunset time.
Args:
observer: Observer to calculate sunset for
date: Date to calculate for. Default is today's date in the timezone `tzinfo`.
tzinfo: Timezone to return times in. Default is UTC.
Returns:
Date and time at which sunset occurs.
Raises:
ValueError: if the sun does not reach the horizon
"""
if isinstance(tzinfo, str):
tzinfo = pytz.timezone(tzinfo)
if date is None:
date = today(tzinfo)
try:
return time_of_transit(
observer, date, 90.0 + SUN_APPARENT_RADIUS, SunDirection.SETTING,
).astimezone(tzinfo)
except ValueError as exc:
if exc.args[0] == "math domain error":
z = zenith(observer, noon(observer, date))
if z > 90.0:
msg = "Sun is always below the horizon on this day, at this location."
else:
msg = "Sun is always above the horizon on this day, at this location."
raise ValueError(msg) from exc
else:
raise
def dusk(
observer: Observer,
date: Optional[datetime.date] = None,
depression: Union[float, Depression] = Depression.CIVIL,
tzinfo: Union[str, datetime.tzinfo] = pytz.utc,
) -> datetime.datetime:
"""Calculate dusk time.
Args:
observer: Observer to calculate dusk for
date: Date to calculate for. Default is today's date in the timezone `tzinfo`.
depression: Number of degrees below the horizon to use to calculate dusk.
Default is for Civil dusk i.e. 6.0
tzinfo: Timezone to return times in. Default is UTC.
Returns:
Date and time at which dusk occurs.
Raises:
ValueError: if dusk does not occur on the specified date
"""
if isinstance(tzinfo, str):
tzinfo = pytz.timezone(tzinfo)
if date is None:
date = today(tzinfo)
dep: float = 0.0
if isinstance(depression, Depression):
dep = depression.value
else:
dep = depression
try:
return time_of_transit(
observer, date, 90.0 + dep, SunDirection.SETTING
).astimezone(tzinfo)
except ValueError as exc:
if exc.args[0] == "math domain error":
raise ValueError(
f"Sun never reaches {dep} degrees below the horizon, at this location."
) from exc
else:
raise
def daylight(
observer: Observer,
date: Optional[datetime.date] = None,
tzinfo: Union[str, datetime.tzinfo] = pytz.utc,
) -> Tuple[datetime.datetime, datetime.datetime]:
"""Calculate daylight start and end times.
Args:
observer: Observer to calculate daylight for
date: Date to calculate for. Default is today's date in the timezone `tzinfo`.
tzinfo: Timezone to return times in. Default is UTC.
Returns:
A tuple of the date and time at which daylight starts and ends.
Raises:
ValueError: if the sun does not rise or does not set
"""
if isinstance(tzinfo, str):
tzinfo = pytz.timezone(tzinfo)
if date is None:
date = today(tzinfo)
start = sunrise(observer, date, tzinfo)
end = sunset(observer, date, tzinfo)
return start, end
def night(
observer: Observer,
date: Optional[datetime.date] = None,
tzinfo: Union[str, datetime.tzinfo] = pytz.utc,
) -> Tuple[datetime.datetime, datetime.datetime]:
"""Calculate night start and end times.
Night is calculated to be between astronomical dusk on the
date specified and astronomical dawn of the next day.
Args:
observer: Observer to calculate night for
date: Date to calculate for. Default is today's date for the
specified tzinfo.
tzinfo: Timezone to return times in. Default is UTC.
Returns:
A tuple of the date and time at which night starts and ends.
Raises:
ValueError: if dawn does not occur on the specified date or
dusk on the following day
"""
if isinstance(tzinfo, str):
tzinfo = pytz.timezone(tzinfo)
if date is None:
date = today(tzinfo)
start = dusk(observer, date, 6, tzinfo)
tomorrow = date + datetime.timedelta(days=1)
end = dawn(observer, tomorrow, 6, tzinfo)
return start, end
def twilight(
observer: Observer,
date: Optional[datetime.date] = None,
direction: SunDirection = SunDirection.RISING,
tzinfo: Union[str, datetime.tzinfo] = pytz.utc,
) -> Tuple[datetime.datetime, datetime.datetime]:
"""Returns the start and end times of Twilight
when the sun is traversing in the specified direction.
This method defines twilight as being between the time
when the sun is at -6 degrees and sunrise/sunset.
Args:
observer: Observer to calculate twilight for
date: Date for which to calculate the times.
Default is today's date in the timezone `tzinfo`.
direction: Determines whether the time is for the sun rising or setting.
Use ``astral.SunDirection.RISING`` or ``astral.SunDirection.SETTING``.
tzinfo: Timezone to return times in. Default is UTC.
Returns:
A tuple of the date and time at which twilight starts and ends.
Raises:
ValueError: if the sun does not rise or does not set
"""
if isinstance(tzinfo, str):
tzinfo = pytz.timezone(tzinfo)
if date is None:
date = today(tzinfo)
start = time_of_transit(observer, date, 90 + 6, direction).astimezone(tzinfo)
if direction == SunDirection.RISING:
end = sunrise(observer, date, tzinfo).astimezone(tzinfo)
else:
end = sunset(observer, date, tzinfo).astimezone(tzinfo)
if direction == SunDirection.RISING:
return start, end
else:
return end, start
def golden_hour(
observer: Observer,
date: Optional[datetime.date] = None,
direction: SunDirection = SunDirection.RISING,
tzinfo: Union[str, datetime.tzinfo] = pytz.utc,
) -> Tuple[datetime.datetime, datetime.datetime]:
"""Returns the start and end times of the Golden Hour
when the sun is traversing in the specified direction.
This method uses the definition from PhotoPills i.e. the
golden hour is when the sun is between 4 degrees below the horizon
and 6 degrees above.
Args:
observer: Observer to calculate the golden hour for
date: Date for which to calculate the times.
Default is today's date in the timezone `tzinfo`.
direction: Determines whether the time is for the sun rising or setting.
Use ``SunDirection.RISING`` or ``SunDirection.SETTING``.
tzinfo: Timezone to return times in. Default is UTC.
Returns:
A tuple of the date and time at which the Golden Hour starts and ends.
Raises:
ValueError: if the sun does not transit the elevations -4 & +6 degrees
"""
if isinstance(tzinfo, str):
tzinfo = pytz.timezone(tzinfo)
if date is None:
date = today(tzinfo)
start = time_of_transit(observer, date, 90 + 4, direction).astimezone(tzinfo)
end = time_of_transit(observer, date, 90 - 6, direction).astimezone(tzinfo)
if direction == SunDirection.RISING:
return start, end
else:
return end, start
def blue_hour(
observer: Observer,
date: Optional[datetime.date] = None,
direction: SunDirection = SunDirection.RISING,
tzinfo: Union[str, datetime.tzinfo] = pytz.utc,
) -> Tuple[datetime.datetime, datetime.datetime]:
"""Returns the start and end times of the Blue Hour
when the sun is traversing in the specified direction.
This method uses the definition from PhotoPills i.e. the
blue hour is when the sun is between 6 and 4 degrees below the horizon.
Args:
observer: Observer to calculate the blue hour for
date: Date for which to calculate the times.
Default is today's date in the timezone `tzinfo`.
direction: Determines whether the time is for the sun rising or setting.
Use ``SunDirection.RISING`` or ``SunDirection.SETTING``.
tzinfo: Timezone to return times in. Default is UTC.
Returns:
A tuple of the date and time at which the Blue Hour starts and ends.
Raises:
ValueError: if the sun does not transit the elevations -4 & -6 degrees
"""
if isinstance(tzinfo, str):
tzinfo = pytz.timezone(tzinfo)
if date is None:
date = today(tzinfo)
start = time_of_transit(observer, date, 90 + 6, direction).astimezone(tzinfo)
end = time_of_transit(observer, date, 90 + 4, direction).astimezone(tzinfo)
if direction == SunDirection.RISING:
return start, end
else:
return end, start
def rahukaalam(
observer: Observer,
date: Optional[datetime.date] = None,
daytime: bool = True,
tzinfo: Union[str, datetime.tzinfo] = pytz.utc,
) -> Tuple[datetime.datetime, datetime.datetime]:
"""Calculate ruhakaalam times.
Args:
observer: Observer to calculate rahukaalam for
date: Date to calculate for. Default is today's date in the timezone `tzinfo`.
daytime: If True calculate for the day time else calculate for the night time.
tzinfo: Timezone to return times in. Default is UTC.
Returns:
Tuple containing the start and end times for Rahukaalam.
Raises:
ValueError: if the sun does not rise or does not set
"""
if isinstance(tzinfo, str):
tzinfo = pytz.timezone(tzinfo)
if date is None:
date = today(tzinfo)
if daytime:
start = sunrise(observer, date, tzinfo)
end = sunset(observer, date, tzinfo)
else:
start = sunset(observer, date, tzinfo)
oneday = datetime.timedelta(days=1)
end = sunrise(observer, date + oneday, tzinfo)
octant_duration = datetime.timedelta(seconds=(end - start).seconds / 8)
# Mo,Sa,Fr,We,Th,Tu,Su
octant_index = [1, 6, 4, 5, 3, 2, 7]
weekday = date.weekday()
octant = octant_index[weekday]
start = start + (octant_duration * octant)
end = start + octant_duration
return start, end
def sun(
observer: Observer,
date: Optional[datetime.date] = None,
dawn_dusk_depression: Union[float, Depression] = Depression.CIVIL,
tzinfo: Union[str, datetime.tzinfo] = pytz.utc,
) -> Dict:
"""Calculate all the info for the sun at once.
Args:
observer: Observer for which to calculate the times of the sun
date: Date to calculate for.
Default is today's date in the timezone `tzinfo`.
dawn_dusk_depression: Depression to use to calculate dawn and dusk.
Default is for Civil dusk i.e. 6.0
tzinfo: Timezone to return times in. Default is UTC.
Returns:
Dictionary with keys ``dawn``, ``sunrise``, ``noon``, ``sunset`` and ``dusk``
whose values are the results of the corresponding functions.
Raises:
ValueError: if passed through from any of the functions
"""
if isinstance(tzinfo, str):
tzinfo = pytz.timezone(tzinfo)
if date is None:
date = today(tzinfo)
return {
"dawn": dawn(observer, date, dawn_dusk_depression, tzinfo),
"sunrise": sunrise(observer, date, tzinfo),
"noon": noon(observer, date, tzinfo),
"sunset": sunset(observer, date, tzinfo),
"dusk": dusk(observer, date, dawn_dusk_depression, tzinfo),
}
Mini Shell