Update tzlocal to 2.1b1

lib/tzlocal/CHANGES.txt

@@ -1,6 +1,15 @@
 Changes
 =======
 
+2.1b1 (2020-02-08)
+------------------
+
+- The is_dst flag is wrong for Europe/Dublin on some Unix releases.
+  I changed to another way of determining if DST is in effect or not.
+
+- Added support for Python 3.7 and 3.8. Dropped 3.5 although it still works.
+
+
 2.0.0 (2019-07-23)
 ------------------
 

lib/tzlocal/unix.py

@@ -138,7 +138,7 @@ def _get_localzone(_root='/'):
     if os.path.exists(tzpath) and os.path.islink(tzpath):
         tzpath = os.path.realpath(tzpath)
         start = tzpath.find("/")+1
-        while start is not 0:
+        while start != 0:
             tzpath = tzpath[start:]
             try:
                 return pytz.timezone(tzpath)

lib/tzlocal/utils.py

@@ -1,5 +1,7 @@
 # -*- coding: utf-8 -*-
+import time
 import datetime
+import calendar
 
 
 def get_system_offset():
@@ -11,8 +13,14 @@ def get_system_offset():
 
     To keep compatibility with Windows, we're always importing time module here.
     """
-    import time
-    if time.daylight and time.localtime().tm_isdst > 0:
+
+    localtime = calendar.timegm(time.localtime())
+    gmtime = calendar.timegm(time.gmtime())
+    offset = gmtime - localtime
+    # We could get the localtime and gmtime on either side of a second switch
+    # so we check that the difference is less than one minute, because nobody
+    # has that small DST differences.
+    if abs(offset - time.altzone) < 60:
         return -time.altzone
     else:
         return -time.timezone

lib/tzlocal/windows_tz.py

@@ -87,6 +87,7 @@ win_tz = {'AUS Central Standard Time': 'Australia/Darwin',
  'Pacific Standard Time (Mexico)': 'America/Tijuana',
  'Pakistan Standard Time': 'Asia/Karachi',
  'Paraguay Standard Time': 'America/Asuncion',
+ 'Qyzylorda Standard Time': 'Asia/Qyzylorda',
  'Romance Standard Time': 'Europe/Paris',
  'Russia Time Zone 10': 'Asia/Srednekolymsk',
  'Russia Time Zone 11': 'Asia/Kamchatka',
@@ -127,6 +128,7 @@ win_tz = {'AUS Central Standard Time': 'Australia/Darwin',
  'Ulaanbaatar Standard Time': 'Asia/Ulaanbaatar',
  'Venezuela Standard Time': 'America/Caracas',
  'Vladivostok Standard Time': 'Asia/Vladivostok',
+ 'Volgograd Standard Time': 'Europe/Volgograd',
  'W. Australia Standard Time': 'Australia/Perth',
  'W. Central Africa Standard Time': 'Africa/Lagos',
  'W. Europe Standard Time': 'Europe/Berlin',
@@ -287,7 +289,7 @@ tz_win = {'Africa/Abidjan': 'Greenwich Standard Time',
  'America/Mendoza': 'Argentina Standard Time',
  'America/Menominee': 'Central Standard Time',
  'America/Merida': 'Central Standard Time (Mexico)',
- 'America/Metlakatla': 'Pacific Standard Time',
+ 'America/Metlakatla': 'Alaskan Standard Time',
  'America/Mexico_City': 'Central Standard Time (Mexico)',
  'America/Miquelon': 'Saint Pierre Standard Time',
  'America/Moncton': 'Atlantic Standard Time',
@@ -347,13 +349,13 @@ tz_win = {'Africa/Abidjan': 'Greenwich Standard Time',
  'America/Winnipeg': 'Central Standard Time',
  'America/Yakutat': 'Alaskan Standard Time',
  'America/Yellowknife': 'Mountain Standard Time',
- 'Antarctica/Casey': 'W. Australia Standard Time',
+ 'Antarctica/Casey': 'Singapore Standard Time',
  'Antarctica/Davis': 'SE Asia Standard Time',
  'Antarctica/DumontDUrville': 'West Pacific Standard Time',
  'Antarctica/Macquarie': 'Central Pacific Standard Time',
  'Antarctica/Mawson': 'West Asia Standard Time',
  'Antarctica/McMurdo': 'New Zealand Standard Time',
- 'Antarctica/Palmer': 'Magallanes Standard Time',
+ 'Antarctica/Palmer': 'SA Eastern Standard Time',
  'Antarctica/Rothera': 'SA Eastern Standard Time',
  'Antarctica/South_Pole': 'New Zealand Standard Time',
  'Antarctica/Syowa': 'E. Africa Standard Time',
@@ -424,7 +426,7 @@ tz_win = {'Africa/Abidjan': 'Greenwich Standard Time',
  'Asia/Pyongyang': 'North Korea Standard Time',
  'Asia/Qatar': 'Arab Standard Time',
  'Asia/Qostanay': 'Central Asia Standard Time',
- 'Asia/Qyzylorda': 'West Asia Standard Time',
+ 'Asia/Qyzylorda': 'Qyzylorda Standard Time',
  'Asia/Rangoon': 'Myanmar Standard Time',
  'Asia/Riyadh': 'Arab Standard Time',
  'Asia/Saigon': 'SE Asia Standard Time',
@@ -592,7 +594,7 @@ tz_win = {'Africa/Abidjan': 'Greenwich Standard Time',
  'Europe/Vatican': 'W. Europe Standard Time',
  'Europe/Vienna': 'W. Europe Standard Time',
  'Europe/Vilnius': 'FLE Standard Time',
- 'Europe/Volgograd': 'Russian Standard Time',
+ 'Europe/Volgograd': 'Volgograd Standard Time',
  'Europe/Warsaw': 'Central European Standard Time',
  'Europe/Zagreb': 'Central European Standard Time',
  'Europe/Zaporozhye': 'FLE Standard Time',