A package to calculate the rise (sunrise) and the set (sunset) of the sun with about minute accuracy.
The calculations are based on the ideas presented at http://lexikon.astronomie.info/zeitgleichung/ (german).
Samples of the results have been successfully compared to http://skycal.com/.
See LICENSE.txt in the repository.
See examples/suncaldemo.go:
import fmt
import suncal
coords := suncal.GeoCoordinates{48.137222, 11.575556}
date := time.Now()
sun := suncal.SunCal(coords, date)
fmt.Printf("Rise %s\nSet %s\n", sun.Rise, sun.Set)Example output:
go run examples/suncaldemo.go
Coordinates Latitude: 48.137222 Longitude 11.575556
Detailed date used 2015-11-19 18:19:46.965911373 +0100 CET
Date 2015-11-20 ↑ 07:27 ↓ 16:30 Δ 9h3m0s
Date 2015-11-21 ↑ 07:28 ↓ 16:29 Δ 9h1m0s
Date 2015-11-22 ↑ 07:29 ↓ 16:28 Δ 8h59m0s
Date 2015-11-23 ↑ 07:31 ↓ 16:27 Δ 8h56m0s
Date 2015-11-24 ↑ 07:32 ↓ 16:26 Δ 8h54m0s
Date 2015-11-25 ↑ 07:34 ↓ 16:25 Δ 8h51m0s
See LICENSE.txt in the repository.
EOF