def sunrise_sunset(moment, latitude, longitude):
r'''Calculates the times at which the sun is at sunset; sunrise; and
halfway between sunrise and sunset (transit).
Uses the Reda and Andreas (2004) model described in [1]_,
originally incorporated into the excellent
`pvlib library <https://github.com/pvlib/pvlib-python>`_
Parameters
----------
moment : datetime
Date for the calculation; needs to contain only the year, month, and
day, [-]
latitude : float
Latitude, between -90 and 90 [degrees]
longitude : float
Longitude, between -180 and 180, [degrees]
Returns
-------
sunrise : datetime
The time at the specified day when the sun rises **IN UTC**, [-]
sunset : datetime
The time at the specified day when the sun sets **IN UTC**, [-]
transit : datetime
The time at the specified day when the sun is at solar noon - halfway
between sunrise and sunset **IN UTC**, [-]
Examples
--------
>>> sunrise, sunset, transit = sunrise_sunset(datetime(2018, 4, 17),
... 51.0486, -114.07)
>>> sunrise
datetime.datetime(2018, 4, 17, 12, 36, 55, 782660)
>>> sunset
datetime.datetime(2018, 4, 18, 2, 34, 4, 249326)
>>> transit
datetime.datetime(2018, 4, 17, 19, 35, 46, 686265)
Notes
-----
This functions takes on the order of 2 ms per calculation.
The reason the function cannot return the time correct the local
timezone is that the function does not know the timezone at the specified
lat/long.
References
----------
.. [1] Reda, Ibrahim, and Afshin Andreas. "Solar Position Algorithm for
Solar Radiation Applications." Solar Energy 76, no. 5 (January 1, 2004):
577-89. https://doi.org/10.1016/j.solener.2003.12.003.
'''
from fluids.optional import spa
delta_t = spa.calculate_deltat(moment.year, moment.month)
# Strip the part of the day
moment = datetime(moment.year, moment.month, moment.day)
import calendar
unixtime = calendar.timegm(moment.timetuple())
unixtime = unixtime - unixtime % (
86400
) # Remove the remainder of the value, rounding it to the day it is
transit, sunrise, sunset = spa.transit_sunrise_sunset(np.array([unixtime]),
lat=latitude,
lon=longitude,
delta_t=delta_t,
numthreads=1)
transit = datetime.utcfromtimestamp(float(transit))
sunrise = datetime.utcfromtimestamp(float(sunrise))
sunset = datetime.utcfromtimestamp(float(sunset))
return sunrise, sunset, transit
def sunrise_sunset(moment, latitude, longitude):
r'''Calculates the times at which the sun is at sunset; sunrise; and
halfway between sunrise and sunset (transit).
Uses the Reda and Andreas (2004) model described in [1]_,
originally incorporated into the excellent
`pvlib library <https://github.com/pvlib/pvlib-python>`_
Parameters
----------
moment : datetime
Date for the calculation; needs to contain only the year, month, and
day; if it is timezone-aware, the return values will be localized to
this timezone [-]
latitude : float
Latitude, between -90 and 90 [degrees]
longitude : float
Longitude, between -180 and 180, [degrees]
Returns
-------
sunrise : datetime
The time at the specified day when the sun rises **IN UTC IF MOMENT
DOES NOT HAVE A TIMEZONE, OTHERWISE THE TIMEZONE GIVEN WITH IT**, [-]
sunset : datetime
The time at the specified day when the sun sets **IN UTC IF MOMENT
DOES NOT HAVE A TIMEZONE, OTHERWISE THE TIMEZONE GIVEN WITH IT**, [-]
transit : datetime
The time at the specified day when the sun is at solar noon - halfway
between sunrise and sunset **IN UTC IF MOMENT
DOES NOT HAVE A TIMEZONE, OTHERWISE THE TIMEZONE GIVEN WITH IT**, [-]
Examples
--------
>>> sunrise, sunset, transit = sunrise_sunset(datetime(2018, 4, 17),
... 51.0486, -114.07)
>>> sunrise
datetime.datetime(2018, 4, 17, 12, 36, 55, 782660)
>>> sunset
datetime.datetime(2018, 4, 18, 2, 34, 4, 249326)
>>> transit
datetime.datetime(2018, 4, 17, 19, 35, 46, 686265)
Example with time zone:
>>> import pytz
>>> sunrise_sunset(pytz.timezone('America/Edmonton').localize(datetime(2018, 4, 17)), 51.0486, -114.07)
(datetime.datetime(2018, 4, 16, 6, 39, 1, 570479, tzinfo=<DstTzInfo 'America/Edmonton' MDT-1 day, 18:00:00 DST>), datetime.datetime(2018, 4, 16, 20, 32, 25, 778162, tzinfo=<DstTzInfo 'America/Edmonton' MDT-1 day, 18:00:00 DST>), datetime.datetime(2018, 4, 16, 13, 36, 0, 386341, tzinfo=<DstTzInfo 'America/Edmonton' MDT-1 day, 18:00:00 DST>))
Note that the year/month/day as input with a timezone, is converted to UTC
time as well.
Notes
-----
This functions takes on the order of 2 ms per calculation.
References
----------
.. [1] Reda, Ibrahim, and Afshin Andreas. "Solar Position Algorithm for
Solar Radiation Applications." Solar Energy 76, no. 5 (January 1, 2004):
577-89. https://doi.org/10.1016/j.solener.2003.12.003.
'''
from fluids.optional import spa
import calendar
if moment.utcoffset() is not None:
moment_utc = moment + moment.utcoffset()
else:
moment_utc = moment
delta_t = spa.calculate_deltat(moment_utc.year, moment_utc.month)
# Strip the part of the day
ymd_moment_utc = datetime(moment_utc.year, moment_utc.month, moment_utc.day)
unixtime = calendar.timegm(ymd_moment_utc.utctimetuple())
unixtime = unixtime - unixtime % (86400) # Remove the remainder of the value, rounding it to the day it is
transit, sunrise, sunset = spa.transit_sunrise_sunset(unixtime, lat=latitude, lon=longitude, delta_t=delta_t)
transit = datetime.utcfromtimestamp(transit)
sunrise = datetime.utcfromtimestamp(sunrise)
sunset = datetime.utcfromtimestamp(sunset)
if moment.tzinfo is not None:
sunrise = moment.tzinfo.fromutc(sunrise)
sunset = moment.tzinfo.fromutc(sunset)
transit = moment.tzinfo.fromutc(transit)
return sunrise, sunset, transit
def sunrise_sunset(moment, latitude, longitude):
r'''Calculates the times at which the sun is at sunset; sunrise; and
halfway between sunrise and sunset (transit).
Uses the Reda and Andreas (2004) model described in [1]_,
originally incorporated into the excellent
`pvlib library <https://github.com/pvlib/pvlib-python>`_
Parameters
----------
moment : datetime
Date for the calculationl; needs to contain only the year, month, and
day, [-]
latitude : float
Latitude, between -90 and 90 [degrees]
longitude : float
Longitude, between -180 and 180, [degrees]
Returns
-------
sunrise : datetime
The time at the specified day when the sun rises **IN UTC**, [-]
sunset : datetime
The time at the specified day when the sun sets **IN UTC**, [-]
transit : datetime
The time at the specified day when the sun is at solar noon - halfway
between sunrise and sunset **IN UTC**, [-]
Examples
--------
>>> sunrise, sunset, transit = sunrise_sunset(datetime(2018, 4, 17),
... 51.0486, -114.07)
>>> sunrise
datetime.datetime(2018, 4, 17, 12, 36, 55, 782660)
>>> sunset
datetime.datetime(2018, 4, 18, 2, 34, 4, 249326)
>>> transit
datetime.datetime(2018, 4, 17, 19, 35, 46, 686265)
Notes
-----
This functions takes on the order of 2 ms per calculation.
The reason the function cannot return the time correct the local
timezone is that the function does not know the timezone at the specified
lat/long.
References
----------
.. [1] Reda, Ibrahim, and Afshin Andreas. "Solar Position Algorithm for
Solar Radiation Applications." Solar Energy 76, no. 5 (January 1, 2004):
577-89. https://doi.org/10.1016/j.solener.2003.12.003.
'''
from fluids.optional import spa
delta_t = spa.calculate_deltat(moment.year, moment.month)
# Strip the part of the day
moment = datetime(moment.year, moment.month, moment.day)
import calendar
unixtime = calendar.timegm(moment.timetuple())
unixtime = unixtime - unixtime % (86400) # Remove the remainder of the value, rounding it to the day it is
transit, sunrise, sunset = spa.transit_sunrise_sunset(np.array([unixtime]), lat=latitude, lon=longitude, delta_t=delta_t, numthreads=1)
transit = datetime.utcfromtimestamp(float(transit))
sunrise = datetime.utcfromtimestamp(float(sunrise))
sunset = datetime.utcfromtimestamp(float(sunset))
return sunrise, sunset, transit