- Rebase to 2015a
  - New leap second 2015-06-30 23:59:60 UTC as per IERS Bulletin C 49.
  - The Mexican state of Quintana Roo, represented by America/Cancun,
    will shift from Central Time with DST to Eastern Time without DST
    on 2015-02-01 at 02:00.
  - Chile will not change clocks in April or thereafter; its new 
    standard time will be its old daylight saving time.  This affects 
    America/Santiago, Pacific/Easter, and Antarctica/Palmer.

- Rebase to 2014j
  - Turks & Caicos' switch from US eastern time to UTC-4 year-round
    did not occur on 2014-11-02 at 02:00.  It's currently scheduled
    for 2015-11-01 at 02:00.

- Rebase to 2014i
  - Pacific/Fiji will observe DST from 2014-11-02 02:00 to 2015-01-18 03:00.
  - A new Zone Pacific/Bougainville, for the part of Papua New Guinea
    that plans to switch from UTC+10 to UTC+11 on 2014-12-28 at 02:00.

- Rebase to 2014h
  - Changes to historical transitions in America/Jamaica and
    Asia/Novokuznetsk.
  - Africa/{Blantyre, Bujumbura, Gaborone, Harare, Kigali, Lubumbashi,
    Lusaka} now alias Africa/Maputo, because they don't differ in
    post-1970 stamps.
  - Africa/Maseru and Africa/Mbabane now alias Africa/Johannesburg for
    the same reason.

- Rebase to 2014g
  - Turks & Caicos is switching from US eastern time to UTC-4
    year-round, modeled as a switch from EST/EDT to AST
    on 2014-11-02 at 02:00.

- Rebase to 2014f
  - Several Russian time zones changes effective on 2014-10-26 
    at 02:00 local time.  See NEWS file for additional details.

- Rebase to 2014e
  - Morrocco suspends DTS for Ramadan 
       June 28 at 03:00 and August 2 at 02:00
  - Egypt suspends DTS for Ramadan
       June 26 and July 31 at 24:00

- Rebase to 2014d
  - zic no longer generates files containing time stamps before
    the Big Bang.  This works around GNOME bug 730332