|FeedbackBy Preston Hunt, 23 January 2011|
I wanted to add a feature to Presto's Sidebar Clock that would automatically adjust the color of the clock based on the time of day. Because the clock has support for international time zones, I thought it might be helpful to know whether it was day or night in the other time zones that a user tracks.
Eventually, I found a page with the calculations and decided it would be faster to go ahead and write it myself from the grounds up. I've generalized it a bit and made it a class in the hopes that other developers can use it.
Here's how you use it:
var tokyo = new SunriseSunset( 2011, 1, 19, 35+40/60, 139+45/60); tokyo.sunriseUtcHours() --> 21.8199 = 21:49 GMT tokyo.sunsetUtcHours() --> 7.9070 = 07:54 GMT tokyo.sunriseLocalHours(9) --> 6.8199 = 06:49 at GMT+9 tokyo.sunsunsetLocalHours(9) --> 16.9070 = 16:54 at GMT+9 tokyo.isDaylight(1.5) --> true
The code is available under an Apache 2.0 License on Pastebin.
Are you using my code in your project? Did you find a bug? Let me know!blog comments powered by Disqus