Your example of “New X” is spot on, because there was a timezone with that name, “US/Pacific-New”, which was different than “US/Pacific”. Bit of history: it was added to some timezone libraries because there was a bill in congress to add it, but it never passed. I had to fix a bug because users were getting set with that timezone and then other systems/libraries were barfing on it…

https://github.com/moment/moment-timezone/issues/498