From c59e6a2750248818f2e77afe321fa96d23719f9c Mon Sep 17 00:00:00 2001
From: Anthony Tuininga <anthony.tuininga@gmail.com>
Date: Tue, 9 May 2023 16:49:31 -0600
Subject: [PATCH] Added support for the ORA_SDTZ environment variable used to
 set the session time zone used by the database.

---
 doc/src/release_notes.rst           |  2 ++
 src/oracledb/impl/thin/messages.pyx | 20 +++++++++++---------
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/doc/src/release_notes.rst b/doc/src/release_notes.rst
index c795fb8..d299feb 100644
--- a/doc/src/release_notes.rst
+++ b/doc/src/release_notes.rst
@@ -13,6 +13,8 @@ oracledb 1.4.0 (TBD)
 Thin Mode Changes
 +++++++++++++++++
 
+#)  Added support for the ``ORA_SDTZ`` environment variable used to set the
+    session time zone used by the database.
 #)  Added support for shrinking the pool back to the minimum number of
     connections allowed in the pool when the pool is idle for
     :data:`ConnectionPool.timeout` seconds.
diff --git a/src/oracledb/impl/thin/messages.pyx b/src/oracledb/impl/thin/messages.pyx
index 6bbd219..0500ea5 100644
--- a/src/oracledb/impl/thin/messages.pyx
+++ b/src/oracledb/impl/thin/messages.pyx
@@ -1394,15 +1394,17 @@ cdef class AuthMessage(Message):
         cdef:
             int tz_hour, tz_minute, timezone
             str sign, tz_repr
-        timezone = -time.altzone if time.daylight else -time.timezone
-        tz_hour = timezone // 3600
-        tz_minute = (timezone - (tz_hour * 3600)) // 60
-        if tz_hour < 0:
-            sign = "-"
-            tz_hour = -tz_hour
-        else:
-            sign = "+"
-        tz_repr = f"{sign}{tz_hour:02}:{tz_minute:02}"
+        tz_repr = os.environ.get("ORA_SDTZ")
+        if tz_repr is None:
+            timezone = -time.altzone if time.daylight else -time.timezone
+            tz_hour = timezone // 3600
+            tz_minute = (timezone - (tz_hour * 3600)) // 60
+            if tz_hour < 0:
+                sign = "-"
+                tz_hour = -tz_hour
+            else:
+                sign = "+"
+            tz_repr = f"{sign}{tz_hour:02}:{tz_minute:02}"
         return f"ALTER SESSION SET TIME_ZONE='{tz_repr}'\x00"
 
     cdef tuple _get_version_tuple(self, ReadBuffer buf):