[tz] please do not enforce limits in code for time zones

[Paul Eggert]

On 01/22/2018 10:55 AM, Steve Allen wrote:
> The traditional calendar for observing at Lick Observatory has always
> had days begin at local noon.  This means that the time zone for the
> Lick calendar is 20 hours behind Greenwich.

You should be OK with tzcode or with any other POSIX-conforming 
implementation, since POSIX requires support for UTC offsets up to 25 
hours. I don't offhand know what tzcode's limits are in this area; at 
some point integer overflow kicks in, if nothing else does.