Author: John Ralls <[hidden email]>
Date: Fri Nov 2 10:29:52 2018 -0700
Bug 795080 - Some dates reset to 01/01/1970
The first fix for this bug handled structs tm with ambiguous times.
This one fixes the GncDate constructor when the time is ambiguous
because it's in the DST-change hour, using the same add 3 hours,
construct the LDT, and subtract the 3 hours from the result.
The string constructor handles only simple-offset HH:MM timezones and so
is immune to the bug.