diff --git a/src/engine/objects/Mine.java b/src/engine/objects/Mine.java
index e7ca5649..1896e549 100644
--- a/src/engine/objects/Mine.java
+++ b/src/engine/objects/Mine.java
@@ -329,7 +329,7 @@ public class Mine extends AbstractGameObject {
 
 
         writer.putLocalDateTime(mineOpenTime);
-        writer.putLocalDateTime(mineOpenTime.plusHours(1));
+        writer.putLocalDateTime(mineOpenTime.plusMinutes(30));
         writer.put(mine.isActive ? (byte) 0x01 : (byte) 0x00);
 
         Building mineTower = BuildingManager.getBuilding(mine.buildingID);