diff --git a/sys/include/timex.h b/sys/include/timex.h
index 8ef77931b7cb58ce30e736eeee22384f52b694cc..4c8a98d47a9ae055c6dac923ed9f207dc69c3dac 100644
--- a/sys/include/timex.h
+++ b/sys/include/timex.h
@@ -33,6 +33,16 @@ extern "C" {
  */
 #define SEC_IN_USEC (1000000U)
 
+/**
+ * @brief The number of seconds per minute
+ */
+#define MIN_IN_SEC  (60U)
+
+/**
+ * @brief The number of centiseconds per second
+ */
+#define SEC_IN_CS   (100U)
+
 /**
  * @brief The number of milliseconds per second
  */