[tz] Converting cities to tz identifiers (tangent)

[Paul Eggert]

On 02/20/2018 02:43 PM, J Andrew Lipscomb wrote:
> For the USA, does city mean the metro area or the city proper?

I expect it'd partly depend on whether the area is likely to split time 
zones. For some metro areas (Denver, say) that's unlikely, for others 
(New York City metro area, which crosses state-line boundaries) it would 
be more of an issue. Cities have split time zones in the past 
(Asia/Nicosia comes to mind) so this issue isn't entirely theoretical.