[tz] Will you add America/Boston?

[Guy Harris]

On Jan 30, 2018, at 3:05 PM, Paul G <paul at ganssle.io> wrote:

> I imagine this will happen if Massachusetts goes through with the change to year round Atlantic Time, but otherwise the name of the zone Boston is in is America/New_York. I believe the zone naming is explained in the theory file. Long story short: tzdb is not a mapping between cities and their time zone, it's a list of time zones which happen to use city names as keys.

Or, rather, a list of regions of the earth that have observed the same time rules since 1970, which happen to be identified by keys constructed from city names.  A given tzdb region may move from one "time zone", in the sense in which it's often understood, to another "time zone", e.g., as the northamerica file in the tzdb data says, "Oliver County, ND switched from mountain to central time on 1992-10-25.", so America/North_Dakota/Center refers to a region that was part of the US Mountain time zone until 1992-10-25 and then was part of the US Central time zone.