[tz] [PROPOSED] zic option for including data from a certain year onward

[Paul Eggert]

On 3/14/19 5:31 PM, Tim Parenti wrote:
> I have a quibble with a small assertion in your patch notes:
>
>     It’s nicer (though not required by RFC 8536) that when the start
>     of a TZif file is truncated, the default time type is that of
>     timestamps just before the first transition.
>
>
> Section 5.1 of RFC 8536 requires that "[a]ll represented information
> that falls inside the truncation range MUST be the same as that
> represented by a corresponding untruncated TZif file."

Yes, my comment was intended to refer only to the default time type in
the 32-bit data. Sorry, my comment did not make that intent clear - and
I don't now recall whether the default time type in the 64-bit area was
also buggy, but it shouldn't matter now since it should be fixed now.

You're right about the default time type in the 64-bit data, which is
what RFC 8536 section 5.1 is talking about. Section 5.1 deliberately
does not place a similar requirement on the 32-bit data; this is so that
zic can still cater to buggy old 32-bit clients.