This page uses the Astral package from sffjunkie:
pip install astral or pip3 install astral or python3.11 -m pip install astralCopied from https://astral.readthedocs.io/en/stable/index.html
from astral import LocationInfo
city = LocationInfo('London', 'England', 'Europe/London', 51.5, -0.116)
print((
f'Information for {city.name}/{city.region}\n'
f'Timezone: {city.timezone}\n'
f'Latitude: {city.latitude:.02f}; Longitude: {city.longitude:.02f}\n'
))
import datetime
from astral.sun import sun
s = sun(city.observer, date=datetime.date(2009, 4, 22))
print((
f'Dawn: {s["dawn"]}\n'
f'Sunrise: {s["sunrise"]}\n'
f'Noon: {s["noon"]}\n'
f'Sunset: {s["sunset"]}\n'
f'Dusk: {s["dusk"]}\n'
))## Information for London/England
## Timezone: Europe/London
## Latitude: 51.50; Longitude: -0.12
##
## Dawn: 2009-04-22 04:13:04.997608+00:00
## Sunrise: 2009-04-22 04:50:17.127004+00:00
## Noon: 2009-04-22 11:59:02+00:00
## Sunset: 2009-04-22 19:08:41.711407+00:00
## Dusk: 2009-04-22 19:46:06.423846+00:00The above code works fine, but it doesn’t take daylight savings into account! Let’s start by getting a function that indicates whether DST is in effect at a particular time and location by generating a Boolean (True/False). Credit for this code goes to https://stackoverflow.com/questions/2881025/python-daylight-savings-time
import pytz
def is_dst(dt=None, timezone='UTC'):
"""Is daylight savings in effect?"""
if dt is None:
dt = datetime.datetime.utcnow()
timezone = pytz.timezone(timezone)
timezone_aware_date = timezone.localize(dt, is_dst=None)
return timezone_aware_date.tzinfo._dst.seconds != 0Let’s try it out for two dates: one in January and one in July:
# Is daylight savings in effect on 1 January?
date = datetime.datetime(2020, 1, 1)
print(is_dst(date, timezone='Europe/London'))
# Is daylight savings in effect on 1 July?
date = datetime.datetime(2020, 7, 1)
print(is_dst(date, timezone='Europe/London'))## False## TrueIncorporating this into the sunrise/sunset times code allows us to add an hour to times that fall during DST:
# Pick a date during DST
date = datetime.datetime(2020, 9, 17)
# Get the unadjusted sunrise and sunset times
city = LocationInfo('Oxford', 'England', 'Europe/London', 51.738931, -1.246467)
s = sun(city.observer, date=date)
sunrise = s['sunrise']
sunset = s['sunset']
# Initialise a time zone
timezone = 'GMT'
# Is daylight savings in effect?
if is_dst(date, timezone='Europe/London'):
# If DST is in effect, add an hour and change the time zone
tdelta = datetime.timedelta(hours=1)
sunrise = sunrise + tdelta
sunset = sunset + tdelta
timezone = 'BST'
# Re-format
sunrise = sunrise.strftime(f'%H:%M {timezone}')
sunset = sunset.strftime(f'%H:%M {timezone}')
print(f'Sunrise: {sunrise}, sunset: {sunset}')## Sunrise: 06:43 BST, sunset: 19:13 BSTTurn the above code into a function to be able to call it easily on multiple days:
def sunrise_sunset(date):
"""Get the sunrise and sunset times adjusted for DST."""
# 'date' is taken at midnight, but daylight savings starts/ends at 1am/2am
# so move the time to midday to be accurate
tdelta = datetime.timedelta(hours=12)
date = date + tdelta
# Get the unadjusted sunrise and sunset times
city = LocationInfo(
'Oxford', 'England', 'Europe/London', 51.738931, -1.246467
)
s = sun(city.observer, date=date)
sunrise = s['sunrise']
sunset = s['sunset']
# Initialise a time zone
timezone = 'GMT'
# Is daylight savings in effect?
if is_dst(date, timezone='Europe/London'):
tdelta = datetime.timedelta(hours=1)
sunrise = sunrise + tdelta
sunset = sunset + tdelta
timezone = 'BST'
# To be conservative, round the time up to the nearest minute
if sunrise.second > 0:
sunrise = sunrise + datetime.timedelta(minutes=1)
if sunrise.second > 13:
sunset = sunset + datetime.timedelta(minutes=1)
# Re-format
sunrise = sunrise.strftime(f'%H:%M {timezone}')
sunset = sunset.strftime(f'%H:%M {timezone}')
return sunrise, sunsetLet’s try it out for two days, one before and one during daylight savings (which in the UK in 2020 started at 1am on 29 March):
# 28 March 2020
date = datetime.datetime(2020, 3, 28)
sunrise, sunset = sunrise_sunset(date)
print(f'Sunrise: {sunrise}, sunset: {sunset}')## Sunrise: 05:49 GMT, sunset: 18:33 GMT# 29 March 2020
date = datetime.datetime(2020, 3, 29)
sunrise, sunset = sunrise_sunset(date)
print(f'Sunrise: {sunrise}, sunset: {sunset}')## Sunrise: 06:47 BST, sunset: 19:34 BSTAs there is a jump of about an hour between these two sets of times, it looks like we’re correct.
To get the sunrise and sunset times for every day in one or more consecutive months we will need to import Python’s built-in calendar functionality:
import calendar
# Create a calendar
cal = calendar.Calendar()This calendar object has the method .itermonthdates() which will generate all the days in a given month in a given year (ie it will generate the numbers 1 to 30 if it it supplied with “September”, 1 to 31 if it is supplied with “October” and so on). We can use this to generate all the sunrise and sunset times for any number of consecutive months starting at a month of our choosing:
import numpy as np
# Choose a start year and month
start_year = 2022
start_month = 4
# Initialise output lists
dates = []
sunrises = []
sunsets = []
# Iterate over four months
for i in range(4):
month = start_month + i
# If you overflow the year, move to the next year
year = int(start_year + np.floor((month - 1) / 12))
# Similarly correct the month
month = month % 12
if month == 0:
month = 12
# For each day in that month in that year
for day in cal.itermonthdates(year, month):
if day.month == month:
day_datetime = datetime.datetime(day.year, day.month, day.day)
sunrise, sunset = sunrise_sunset(day_datetime)
dates.append(day.strftime('%Y-%m-%d'))
sunrises.append(sunrise)
sunsets.append(sunset)
# Create list-of-lists
ls_of_ls = [dates, sunrises, sunsets]
print(
f'Dates: {ls_of_ls[0][:5]}',
f'Sunrises: {ls_of_ls[1][:5]}',
f'Sunsets: {ls_of_ls[2][:5]}',
sep='\n'
)## Dates: ['2022-04-01', '2022-04-02', '2022-04-03', '2022-04-04', '2022-04-05']
## Sunrises: ['06:41 BST', '06:39 BST', '06:37 BST', '06:34 BST', '06:32 BST']
## Sunsets: ['19:39 BST', '19:40 BST', '19:41 BST', '19:44 BST', '19:45 BST']Finally, let’s export these results to a CSV file:
import csv
# Export list-of-lists to comma-separated values (.csv)
with open('sunrise_sunset.csv', 'w', newline='') as file:
a = csv.writer(file, delimiter=',')
a.writerows(ls_of_ls)