[Remind-Fans] dawn,sunrise,sunset, dusk -- solar_noon??

[Dianne Skoll]

On 2020-10-10 07:01, remind-fans at trodman.com wrote:

> How about adding

>     noon_solar() ?

> Right now, might I be able to do the math all in remind, and bisect the
> sunrise(),sunset() interval?

Yep.  I believe solar noon is defined as halfway between sunrise and
sunset, so this will do the trick:

    FSET solarnoon(x) sunrise(x) + (sunset(x)-sunrise(x))/2
    MSG Sunrise: [sunrise($T)]; Sunset: [sunset($T)]; Solar noon: [solarnoon($T)]

Note that because of how Remind converts types, the simpler:

    FSET solarnoon(x) (sunrise(x) + sunset(x)) / 2

will not work.  You cannot divide a time by an integer, so you get:

    `/': Type mismatch

However, subtracting two times yields an integer, which *can* be divided
by two, and you can add an integer to a time, so it all works out.

Regards,

Dianne.