Fixed #37110 -- Fixed time zone validation when missing zone directory.

On Unix systems that lack time zone information stored at
`/usr/share/zoneinfo`, time zones couldn't be validated.

Python's `zoneinfo` module was introduced in Python 3.9, meaning all
modern Django versions should support it's use.

2 files changed, 5 insertions, 6 deletions

diff --git a/AUTHORS b/AUTHORS
index 36914d2950..1385cc5afd 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -533,6 +533,7 @@ answer newbie questions, and generally made Django that much better:
     Joachim Jablon <ewjoachim@gmail.com>
     Joao Oliveira <joaoxsouls@gmail.com>
     Joao Pedro Silva <j.pedro004@gmail.com>
+    jodizzle
     Joe Heck <http://www.rhonabwy.com/wp/>
     Joe Jackson <joe@joejackson.me>
     Joel Bohman <mail@jbohman.com>
diff --git a/django/conf/__init__.py b/django/conf/__init__.py
index d462f82acf..020047ffd8 100644
--- a/django/conf/__init__.py
+++ b/django/conf/__init__.py
@@ -10,7 +10,7 @@ import importlib
 import os
 import time
 import warnings
-from pathlib import Path
+import zoneinfo
 
 from django.conf import global_settings
 from django.core.exceptions import ImproperlyConfigured
@@ -295,11 +295,9 @@ class Settings:
             )
 
         if hasattr(time, "tzset") and self.TIME_ZONE:
-            # When we can, attempt to validate the timezone. If we can't find
-            # this file, no check happens and it's harmless.
-            zoneinfo_root = Path("/usr/share/zoneinfo")
-            zone_info_file = zoneinfo_root.joinpath(*self.TIME_ZONE.split("/"))
-            if zoneinfo_root.exists() and not zone_info_file.exists():
+            try:
+                zoneinfo.ZoneInfo(self.TIME_ZONE)
+            except zoneinfo.ZoneInfoNotFoundError:
                 raise ValueError("Incorrect timezone setting: %s" % self.TIME_ZONE)
             # Move the time zone info into os.environ. See ticket #2315 for why
             # we don't do this unconditionally (breaks Windows).