[Remind-Fans] issue warnings for impossible UNTIL ranges

[Ian! D. Allen]

On Wed, Mar 02, 2022 at 08:38:06AM -0500, Dianne Skoll via Remind-fans wrote:
> > Could remind be coaxed into issuing a warning for impossible constant
> > date "UNTIL" and "THROUGH" ranges such as:
> >     REM Mar  1 2022 *1 UNTIL Mar 30 2021 MSG test

We also need a warning for a FROM date that precedes an UNTIL date:

    REM Mon Thu FROM 23 Jul 2022 UNTIL 2 Aug 1999 MSG Test

We also need a warning for a failure to specify a repeat factor with
UNTIL using a specific start date, e.g. this should produce a warning
about a missing repeat factor:

    REM 1992-11-30 UNTIL 1992-12-04 MSG Jury duty

I can't offhand think of a legitimate use of UNTIL with a fully-specified
start date and no repeat factor, so remind should tell me so.

-- 
| Ian! D. Allen, BA-Psych, MMath-CompSci  idallen at idallen.ca Ottawa CANADA
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