diff --git a/du3/program.c b/du3/program.c
index 868e058..da22ada 100644
--- a/du3/program.c
+++ b/du3/program.c
@@ -41,6 +41,10 @@ int main() {
 						puts("Neplatny datum.");
 						goto LABEL;
 					}
+					if(date[0] >= 29 && date[1] == 2 && date[2] % 4 != 0 && (date[2] % 100 == 0 || (date[2] % 100 == 0 && date[2] % 400 != 0))){
+        				puts("Neplatny datum");
+        				goto LABEL;
+   					}
 					date[0] += 7;
 					if(date[0] > 31 && (date[1] == 1 || date[1] == 3 || date[1] == 5 || date[1] == 7 || date[1] == 8 || date[1] == 10 || date[1] == 12)){
 						date[0] -= 31;