diff --git a/du3/program.c b/du3/program.c
index 4aa5baa..fb07489 100644
--- a/du3/program.c
+++ b/du3/program.c
@@ -20,7 +20,7 @@ if(m%2==0 && day>30){
         day-=28;
     }
     else if(m==2){
-        day-=29;
+        day-=30;
     }
     else{
         day-=30;