## Sunrise/Sunset Algo

Latest update:

If you need to implement sunrise/sunset calculations having only a latitude/longitude (& a particular date), look here.

If found that with *zenith = 90.79* it gives the same rise/set numbers
as googling for "<location> sunrise".

Also be careful with defining your sin/asin et al. that should take degrees & return degrees. For example:

```
let sin = (d) => Math.sin(d * (Math.PI / 180))
let asin = (d) => Math.asin(d) * (180/Math.PI)
```

I had to do the same while reviving an old timezone viewer
tktz to force it to work again on
Fedora 23. Of course I forgot that `asin()`

returns radians & was
scratching my head over why I was getting phoney baloney numbers.

Tags: ойті

Authors: ag