There's a new time zone in Windows XP RC1. Here's the diff from its Beta2.

*** winxp-b2.reg Tue May 22 22:12:52 2001
--- winxp-rc1.reg Fri Aug 17 00:11:35 2001
***************
*** 184,190 ****
    00,00,00,00,00,00,00,03,00,00,00,05,00,02,00,00,00,00,00,00,00
  
  [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\Central European Standard Time]
! "Display"="(GMT+01:00) Sarajevo, Skopje, Sofija, Vilnius, Warsaw, Zagreb"
  "Dlt"="Central European Daylight Time"
  "Std"="Central European Standard Time"
  "MapID"="2,3"
--- 184,190 ----
    00,00,00,00,00,00,00,03,00,00,00,05,00,02,00,00,00,00,00,00,00
  
  [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\Central European Standard Time]
! "Display"="(GMT+01:00) Sarajevo, Skopje, Warsaw, Zagreb"
  "Dlt"="Central European Daylight Time"
  "Std"="Central European Standard Time"
  "MapID"="2,3"
***************
*** 220,226 ****
    00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00
  
  [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\Dateline Standard Time]
! "Display"="(GMT-12:00) Eniwetok, Kwajalein"
  "Dlt"="Dateline Daylight Time"
  "Std"="Dateline Standard Time"
  "MapID"="24,25"
--- 220,226 ----
    00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00
  
  [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\Dateline Standard Time]
! "Display"="(GMT-12:00) International Date Line West"
  "Dlt"="Dateline Daylight Time"
  "Std"="Dateline Standard Time"
  "MapID"="24,25"
***************
*** 252,258 ****
  "Std"="E. Europe Standard Time"
  "MapID"="4,5"
  "Index"=dword:00000073
! "TZI"=hex:88,ff,ff,ff,00,00,00,00,c4,ff,ff,ff,00,00,09,00,00,00,05,00,01,00,00, 00,00,00,00,00,00,00,03,00,00,00,05,00,00,00,00,00,00,00,00,00
  
  [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\E. South America Standard Time]
--- 252,258 ----
  "Std"="E. Europe Standard Time"
  "MapID"="4,5"
  "Index"=dword:00000073
! "TZI"=hex:88,ff,ff,ff,00,00,00,00,c4,ff,ff,ff,00,00,0a,00,00,00,05,00,01,00,00, 00,00,00,00,00,00,00,03,00,00,00,05,00,00,00,00,00,00,00,00,00
  
  [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\E. South America Standard Time]
***************
*** 301,307 ****
    00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00
  
  [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\FLE Standard Time]
! "Display"="(GMT+02:00) Helsinki, Riga, Tallinn"
  "Dlt"="FLE Daylight Time"
  "Std"="FLE Standard Time"
  "MapID"="-1,67"
--- 301,307 ----
    00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00
  
  [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\FLE Standard Time]
! "Display"="(GMT+02:00) Helsinki, Kyiv, Riga, Sofia, Tallinn, Vilnius"
  "Dlt"="FLE Daylight Time"
  "Std"="FLE Standard Time"
  "MapID"="-1,67"
***************
*** 355,361 ****
    00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00
  
  [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\India Standard Time]
! "Display"="(GMT+05:30) Calcutta, Chennai, Mumbai, New Delhi"
  "Dlt"="India Daylight Time"
  "Std"="India Standard Time"
  "MapID"="-1,74"
--- 355,361 ----
    00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00
  
  [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\India Standard Time]
! "Display"="(GMT+05:30) Chennai, Kolkata, Mumbai, New Delhi"
  "Dlt"="India Daylight Time"
  "Std"="India Standard Time"
  "MapID"="-1,74"
***************
*** 391,403 ****
    00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00
  
  [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\Mexico Standard Time]
! "Display"="(GMT-06:00) Mexico City"
  "Dlt"="Mexico Daylight Time"
  "Std"="Mexico Standard Time"
  "MapID"="-1,85"
  "Index"=dword:0000001e
! "TZI"=hex:68,01,00,00,00,00,00,00,c4,ff,ff,ff,00,00,0a,00,00,00,05,00,02,00,00,! 00,00,00,00,00,00,00,04,00,00,00,01,00,02,00,00,00,00,00,00,00
  
  [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\Mid-Atlantic Standard Time]
  "Display"="(GMT-02:00) Mid-Atlantic"
--- 391,412 ----
    00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00
  
  [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\Mexico Standard Time]
! "Display"="(GMT-06:00) Guadalajara, Mexico City, Monterrey"
  "Dlt"="Mexico Daylight Time"
  "Std"="Mexico Standard Time"
  "MapID"="-1,85"
  "Index"=dword:0000001e
! "TZI"=hex:68,01,00,00,00,00,00,00,c4,ff,ff,ff,00,00,09,00,00,00,05,00,02,00,00,! 00,00,00,00,00,00,00,05,00,00,00,01,00,02,00,00,00,00,00,00,00
!
! [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\Mexico Standard Time 2]
! "Display"="(GMT-07:00) Chihuahua, La Paz, Mazatlan"
! "Dlt"="Mexico Daylight Time"
! "Std"="Mexico Standard Time"
! "MapID"="34,35"
! "Index"=dword:0000000d
! "TZI"=hex:a4,01,00,00,00,00,00,00,c4,ff,ff,ff,00,00,09,00,00,00,05,00,02,00,00,! 00,00,00,00,00,00,00,05,00,00,00,01,00,02,00,00,00,00,00,00,00
  
  [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones\Mid-Atlantic Standard Time]
  "Display"="(GMT-02:00) Mid-Atlantic"