Updated documentation on setting timezone.

Author: subkanthi

examples/docker-compose/README.md

@@ -28,7 +28,50 @@ Solution: Upgrade docker/docker compose to v2.
 
 ### Supplemental
 
+#### Setting ClickHouse Server Timezone
+
+To configure the ClickHouse server timezone:
+
+1. Edit `config.xml` with your desired timezone:
+
+```xml
+<clickhouse replace="true">
+    <timezone>America/Chicago</timezone>
+</clickhouse>
+```
+
+2. Uncomment the volume mount in `docker-compose.yaml` under the `clickhouse` service:
+
+```yaml
+volumes:
+  - ./config.xml:/etc/clickhouse-server/conf.d/config.xml
+```
+
+3. Restart the containers: `docker compose down && docker compose up`
+
 #### Querying data using Spark
+To set the session timezone in Spark, add the following configuration under the `configs` section in `docker-compose-spark-iceberg.yaml`:
+
+```yaml
+    configs:
+      - spark.sql.session.timeZone=America/Chicago
+```
+
+Replace `America/Chicago` with your desired timezone.
+
+For example, your Spark service definition might look like:
+
+```yaml
+  spark-iceberg:
+    image: ...
+    environment:
+      - ...
+    configs:
+      - spark.sql.session.timeZone=America/Chicago
+    ...
+```
+
+This ensures that Spark SQL sessions will use the specified timezone.
 
 ```shell
 docker compose -f docker-compose-spark-iceberg.yaml down -v

examples/docker-compose/docker-compose.yaml

@@ -53,9 +53,9 @@ services:
     volumes:
       # for access to clickhouse-logs
       - ./data/docker-compose/clickhouse/var/log/clickhouse-server:/var/log/clickhouse-server
-      - ./config.xml:/etc/clickhouse-server/conf.d/config.xml
-     depends_on:
-       - ice-rest-catalog
+      # - ./config.xml:/etc/clickhouse-server/conf.d/config.xml
+    depends_on:
+      - ice-rest-catalog
 configs:
   clickhouse-init:
     content: |