[tz] Dealing with Pre-1970 Data

[Zefram]

Lester Caine wrote:
>                         how do I assess the accuracy of other
>historic data?

This can only be done case-by-case, by examining the extensive commentary
in the source files.  It would be nice to have formalised quality metadata
that could be used programmatically, but it would be an awfully big job
to mark up the existing data to get that system going.  Much easier to
keep it up to date thereafter, though.

Standardising the rounding mode that we use to compute LMT offsets won't
help with this.

-zefram