Solar-Calculator

Calculates the sunrise and sunset for a given date and location (using GEO coordinates). This library uses the method outlined NOAA Solar Calculations Day spreadsheet found at http://www.esrl.noaa.gov/gmd/grad/solcalc/calcdetails.html.

Installing

Add this to your project in Visual Studio using NuGet Package Manager UI and ID SolarCalculator or using the Package Manager Console.

PM> Install-Package SolarCalculator

Notes

Starting in version 3.3.0 there are two new properties for checking if a date is a Polar Day (IsPolarDay) or Polar Night (IsPolarNight). If the combination of date and location result in a Polar Day or Polar Night, the values for Sunrise and Sunset are as follows:

Polar Day: Sunrise = DateTime.MinValue, Sunset = DateTime.MaxValue

Polar Night: Sunrise = DateTime.MaxValue, Sunset = DateTime.MinValue

Sample Code

The sample code below shows how to initialize and call the Solar Calculator to get the sunrise and sunset for the given location.

Sunrise in Chicago

using System;
using Innovative.SolarCalculator;

//
// Geo coordinates of Oak Street Beach in Chicago, IL
//
// NOTE: the .Date is not necessary but is included to demonstrate that time input 
// does not affect the output. Time will be returned in the current time zone so it 
// will need to be adjusted to the time zone where the coordinates are from (there 
// are services that can be used to get time zone from a latitude and longitude position).
//
TimeZoneInfo cst = TimeZoneInfo.FindSystemTimeZoneById("Central Standard Time");
SolarTimes solarTimes = new SolarTimes(DateTime.Now.Date, 41.9032, -87.6224);
DateTime sunrise = TimeZoneInfo.ConvertTimeFromUtc(solarTimes.Sunrise.ToUniversalTime(), cst);

//
// Display the sunrise
//
Console.WriteLine($"View the sunrise across Lake Michigan from Oak Street Beach in Chicago at {sunrise.ToLongTimeString()} on {sunrise.ToLongDateString()}.");

Sunset in Michigan

//
// Geo coordinates of Benton Harbor/Benton Heights in Michigan
//
TimeZoneInfo est = TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time");              
SolarTimes solarTimes = new SolarTimes(DateTime.Now, 42.1543, -86.4459);
DateTime sunset = TimeZoneInfo.ConvertTimeFromUtc(solarTimes.Sunset.ToUniversalTime(), est);

//
// Display the sunset
//
Console.WriteLine($"View the sunset across Lake Michigan from Benton Harbor in Michigan at {sunset.ToLongTimeString()} on {sunset.ToLongDateString()}.");