[Therion] Date before 1900 error - but where?

[Olly Betts]

On Wed, Feb 19, 2025 at 07:39:17PM +0000, Andrew Atkinson wrote:
> That must be a change in Therion (Survex) as that file has not been edited
> since 2013.05.11 and it has been used many many times since the

Nothing to do with Survex here.

Indeed Survex handles the equivalent situation with a clear warning and error
which highlight exactly how this is interpreted and what's wrong with it:

baddaterange.svx:1:18: warning: Assuming 2 digit year is 1913
 *date 2013.04.12-13
                  ^~
baddaterange.svx:1:7: error: End of date range is before the start
 *date 2013.04.12-13
       ^~~~~~~~~~~~~

Cheers,
    Olly