Each primary button has on-line help using the RPN help system. See the example screen below. It's important that your RPN calculator be in Degrees mode. I will add a conversion in the near future that will handle the calculator being in Radian mode. V described below.
Calculations begin by first selecting or entering a date which optionally includes a time with it.
To select today at local midnight press T . MoonFN internally uses UT for calculations. To select 1 to 5 days from today at local midnight, press X . Time should be entered in 24 hour format. To select now, press N .