diff --git a/website/docs/guides/best-practices/how-we-build-our-metrics/semantic-layer-3-build-semantic-models.md b/website/docs/guides/best-practices/how-we-build-our-metrics/semantic-layer-3-build-semantic-models.md
index 2c2122572b8..a2dc55e37ae 100644
--- a/website/docs/guides/best-practices/how-we-build-our-metrics/semantic-layer-3-build-semantic-models.md
+++ b/website/docs/guides/best-practices/how-we-build-our-metrics/semantic-layer-3-build-semantic-models.md
@@ -148,7 +148,9 @@ from source
 
 ```YAML
 dimensions:
-      - name: date_trunc('day', ordered_at)
+      - name: ordered_at
+        expr: date_trunc('day', ordered_at)
+        # use date_trunc(ordered_at, DAY) if using [BigQuery](/docs/build/dimensions#time)
         type: time
         type_params:
           time_granularity: day
@@ -166,7 +168,9 @@ We'll discuss an alternate situation, dimensional tables that have static numeri
 ```YAML
 ...
 dimensions:
-  - name: date_trunc('day', ordered_at)
+  - name: ordered_at
+    expr: date_trunc('day', ordered_at)
+    # use date_trunc(ordered_at, DAY) if using BigQuery
     type: time
     type_params:
       time_granularity: day
@@ -254,6 +258,8 @@ semantic_models:
 
     dimensions:
       - name: ordered_at
+        expr: date_trunc('day', ordered_at)
+        # use date_trunc(ordered_at, DAY) if using BigQuery
         type: time
         type_params:
           time_granularity: day