diff --git a/stacks/famapp/stack.env b/stacks/famapp/stack.env
index 101a0d8..8923272 100644
--- a/stacks/famapp/stack.env
+++ b/stacks/famapp/stack.env
@@ -42,3 +42,5 @@ LLM_PROVIDER=openai
 LLM_BASE_URL=http://192.168.1.121:8080/v1
 LLM_API_KEY=famapp-unc-f04f7ef0baf68d542d10a501
 LLM_MODEL=auto
+# IANA timezone for assistant relative dates ("Thursday at 2")
+HOUSEHOLD_TIMEZONE=America/Chicago