diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 6f03825..2fa9456 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -74,6 +74,17 @@ jobs:
     - name: Create database user
       run: |
         ./ci/setup_accounts.sh
+    - name: Force client TZ data to match server (ORA_TZFILE workaround)
+      run: |
+        ORACLE_CONTAINER=$(docker ps --filter "ancestor=gvenzl/oracle-free" -q)
+        SRC=$(docker exec "$ORACLE_CONTAINER" bash -c 'ls $ORACLE_HOME/oracore/zoneinfo/timezlrg_*.dat 2>/dev/null | head -1')
+        echo "Server TZ file: $SRC"
+        DST_DIR="$ORACLE_HOME/oracore/zoneinfo"
+        sudo mkdir -p "$DST_DIR"
+        docker cp "$ORACLE_CONTAINER":"$SRC" /tmp/_server_tzfile.dat
+        sudo mv /tmp/_server_tzfile.dat "$DST_DIR/$(basename "$SRC")"
+        ls -l "$DST_DIR"
+        echo "ORA_TZFILE=$DST_DIR/$(basename "$SRC")" >> $GITHUB_ENV
     - name: Bundle install
       run: |
         bundle install --jobs 4 --retry 3
diff --git a/.github/workflows/test_gemfiles.yml b/.github/workflows/test_gemfiles.yml
index a92784c..83f3ead 100644
--- a/.github/workflows/test_gemfiles.yml
+++ b/.github/workflows/test_gemfiles.yml
@@ -88,6 +88,17 @@ jobs:
     - name: Create database user
       run: |
         ./ci/setup_accounts.sh
+    - name: Force client TZ data to match server (ORA_TZFILE workaround)
+      run: |
+        ORACLE_CONTAINER=$(docker ps --filter "ancestor=gvenzl/oracle-free" -q)
+        SRC=$(docker exec "$ORACLE_CONTAINER" bash -c 'ls $ORACLE_HOME/oracore/zoneinfo/timezlrg_*.dat 2>/dev/null | head -1')
+        echo "Server TZ file: $SRC"
+        DST_DIR="$ORACLE_HOME/oracore/zoneinfo"
+        sudo mkdir -p "$DST_DIR"
+        docker cp "$ORACLE_CONTAINER":"$SRC" /tmp/_server_tzfile.dat
+        sudo mv /tmp/_server_tzfile.dat "$DST_DIR/$(basename "$SRC")"
+        ls -l "$DST_DIR"
+        echo "ORA_TZFILE=$DST_DIR/$(basename "$SRC")" >> $GITHUB_ENV
     - name: Bundle install
       run: |
         bundle install --jobs 4 --retry 3
diff --git a/.github/workflows/truffleruby.yml b/.github/workflows/truffleruby.yml
index 3789fd2..b4eeeda 100644
--- a/.github/workflows/truffleruby.yml
+++ b/.github/workflows/truffleruby.yml
@@ -63,6 +63,17 @@ jobs:
     - name: Create database user
       run: |
         ./ci/setup_accounts.sh
+    - name: Force client TZ data to match server (ORA_TZFILE workaround)
+      run: |
+        ORACLE_CONTAINER=$(docker ps --filter "ancestor=gvenzl/oracle-free" -q)
+        SRC=$(docker exec "$ORACLE_CONTAINER" bash -c 'ls $ORACLE_HOME/oracore/zoneinfo/timezlrg_*.dat 2>/dev/null | head -1')
+        echo "Server TZ file: $SRC"
+        DST_DIR="$ORACLE_HOME/oracore/zoneinfo"
+        sudo mkdir -p "$DST_DIR"
+        docker cp "$ORACLE_CONTAINER":"$SRC" /tmp/_server_tzfile.dat
+        sudo mv /tmp/_server_tzfile.dat "$DST_DIR/$(basename "$SRC")"
+        ls -l "$DST_DIR"
+        echo "ORA_TZFILE=$DST_DIR/$(basename "$SRC")" >> $GITHUB_ENV
     - name: Bundle install
       run: |
         bundle install --jobs 4 --retry 3