diff --git a/projects/core/src/main/java/dan200/computercraft/core/apis/OSAPI.java b/projects/core/src/main/java/dan200/computercraft/core/apis/OSAPI.java
index e31f76d73..49c75e8cb 100644
--- a/projects/core/src/main/java/dan200/computercraft/core/apis/OSAPI.java
+++ b/projects/core/src/main/java/dan200/computercraft/core/apis/OSAPI.java
@@ -122,7 +122,7 @@ public class OSAPI implements ILuaAPI {
     }
 
     private static long getEpochForCalendar(Calendar c) {
-        return c.getTime().getTime();
+        return c.getTimeInMillis();
     }
 
     /**