sunset
The getSunset method Returns a Date representing the elevation adjusted sunset time. The zenith used for the calculation uses geometric zenith of 90 plus AstronomicalCalculator.getElevationAdjustment. This is adjusted by the AstronomicalCalculator to add approximately 50/60 of a degree to account for 34 archminutes of refraction and 16 archminutes for the sun's radius for a total of 90.83333˚. See documentation for the specific implementation of the AstronomicalCalculator that you are using. Note: In certain cases the calculates sunset will occur before sunrise. This will typically happen when a timezone other than the local timezone is used (calculating Los Angeles sunset using a GMT timezone for example). In this case the sunset date will be incremented to the following date.
Return
the Date representing the exact sunset time. If the calculation can't be computed such as in the Arctic Circle where there is at least one day a year where the sun does not rise, and one where it does not set, a null will be returned. See detailed explanation on top of the page.