diff --git a/shared/src/types.ts b/shared/src/types.ts
index f4b2549..6661777 100644
--- a/shared/src/types.ts
+++ b/shared/src/types.ts
@@ -179,6 +179,7 @@ export interface StateUpdate {
   entities: EntityState[];
   tick: number;
   gameTime: number; // 0.0-1.0 normalized position in day/night cycle
+  dayNumber: number; // 1-indexed day counter
 }
 
 export interface PlayerJoined {