suntimes -- show sunrise and sunset times, etc., on a CP/M system
=================================================================

Usage example
-------------

suntimes lat=51.51 long=0.118 offset=1 date=2023-5-29

Some or all of the command-line arguments can be placed in a configuration
file. The default configuration file is suntimes.ini in the current logged-in
drive. This name and location can be overridden on the command line:

suntimes /c f:suntimes.ini ...

ROMWBW support
--------------

On a ROMWBW machine with real-time clock, suntimes defaults to using the
current date for the calculation. Of course, this can be overridden on the
command line.

Date format
-----------

The date format is YYYY-MM-DD, and this is the only format recognized at
present. If the time is read from a real-time clock, and the year is only two
digits, 2000 is added to it. However, this isn't the case for the command line.

UTC offset
----------

Because CP/M has no timezone database, the user must specify the offset from
UTC (GMT) using the 'offset' command line option. This is the number of hours
ahead of UTC, and can include a fraction.

Latitude and longitude
----------------------

The 'lat' and 'long' arguments are signed fractional degrees. North of the
equator is a positive longitude, east of Greenwich is a positive latitude.