Is this because we do not initialize tm fields to "unknown" in the
beginning? I admit I haven't bothered to look at this part of the code
for a looong time.
Indeed. The _exact_ date handling initializes the date to -1 (and the
time to 0), but the approxidate thing defaults to "now" and then modifies
that.
Which is why we'd need to have a separate flags field for "I have
initialized this field".
Linus