diff --git a/src/planner.c b/src/planner.c
index 1684d3b..5494d33 100644
--- a/src/planner.c
+++ b/src/planner.c
@@ -15,6 +15,10 @@
 #include <string.h>
 #include <time.h>
 
+#define ctime_r(T,Tm) (localtime_s(Tm,T) ? NULL:Tm)
+#define localtime_r(T,Tm) (localtime_s(Tm,T) ? NULL:Tm)
+
+
 const uint intervalLen = 45; // min
 const uint pauseLen = 10;    //