diff --git a/datetime/arithmetic.c b/datetime/arithmetic.c
index 3d75f8d..f5c7033 100644
--- a/datetime/arithmetic.c
+++ b/datetime/arithmetic.c
@@ -24,7 +24,7 @@ int wmain(void) {
     FileTimeToSystemTime(&ft, &st);
 
     wprintf(L"%02d/%02d/%04d %02d:%02d:%02d\n",
-        st.wDay,st.wMonth,st.wYear,st.wHour,st.wMinute,st.wSecond);
+        st.wDay, st.wMonth, st.wYear, st.wHour, st.wMinute, st.wSecond);
 
     return 0;
 }