Change Opacity of a Layer at Sunrise and Sunset

Do you want a layer to change with the sunset and sunrise? Add this snippet of code to the selected layers opacity setting to change it from 100% visible to 40% visible. You can change the "100" or the "40" at the end of the code snippet to acheive your own desired effect. Thanks to Frank Defaux for the code.

{dtp}>{wsrp} and {dtp}<{wssp} and 100 or 40