[Remind-Fans] Faking the time zone (was Re: sun moon data)

[Edward Shapard]

I have some solar time functions that I use to calculate solar noon and 
solar midnight.

```
FSET _light_len(date) MAX(SUNSET(date)-SUNRISE(date), 0)
FSET _dark_len(date) 1440-_light_len(date)
FSET _solar_noon(date) sunrise(date) + (_light_len(date)/2)
FSET _solar_midnight(date) sunset(date) + (_dark_len(date)/2)
```

It's not as compact as Diane's suggestion, but I can do things like 
report how many daylight hours there will be on a certain day.

You can call it like so:

```
REM [today()] AT [_solar_noon(today())] MSG 🌞Solar Noon!
```

Excerpts from Sector11 via Remind-fans's message of March 18, 2022 8:10 am:
> Dianne you are going above and beyond the call of duty here.
> 
> I never thought to use TZ.
> Using TX as shown do your also get:
> ----------
> Mittagssonne: 361
> ----------
> for solar noon?
> 
> Thank you
> Bruce
> 
> 
> On Thu, 17 Mar 2022 16:52:10 -0400
> Dianne Skoll via Remind-fans <remind-fans at lists.skoll.ca> wrote:
> 
>> On Thu, 17 Mar 2022 11:54:33 -0300
>> Sector11 via Remind-fans <remind-fans at lists.skoll.ca> wrote:
>> 
>> > Dianne I feel so silly and:
>> > -----
>> > faketime -f '+4' remind -q -r ~/.reminders.sun.v
>> > -----
>> > doesn't work.  :(  
>> 
>> No, but:
>> 
>>     TZ=Europe/Berlin remind -q -r ~/.reminders.sun.v
>> 
>> might.
>> 
>> Now I do see that it's off by about 10-12 minutes from
>> some sources on the web, so I might need to investigate
>> further.
>> 
>> Regards,
>> 
>> Dianne.
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