diff --git a/devser.h b/devser.h
index 897c1471..b2e48c93 100644
--- a/devser.h
+++ b/devser.h
@@ -97,7 +97,7 @@ int DevQueue(DevSer * devser, void *actionData, DevPrio prio,
              DevActionHandler * hdl, DevActionMatch * matchFunc,
              DevKillActionData * killFunc, DevInfoFunc * infoFunc);
 
-/** \brief Schedule a periodic action
+/** \brief Schedule a periodic action, with specified start
  *
  * If a matching action exists already,
  *   it is overwritten with a possibly changed interval and priority.
@@ -105,6 +105,9 @@ int DevQueue(DevSer * devser, void *actionData, DevPrio prio,
  * \param actionData the action data
  * \param prio the priority
  * \param interval the interval in seconds (0 is allowed)
+ * \param start  the first call time. if a passed time is specified,
+ *    the next call happens immediately, and further calls happen after
+ *    start + n * interval
  * \param hdl the action handler
  * \param matchFunc a match function with two arguments of the same type
  * \param killFunc the action data kill function or NULL if no kill function is needed.
@@ -113,6 +116,15 @@ int DevQueue(DevSer * devser, void *actionData, DevPrio prio,
  * \return 1 when this was a new action, 0 when an action was overwritten
  *        in the second case the actionData's kill Function is immediately called
  */
+int DevScheduleS(DevSer * devser, void *actionData,
+                DevPrio prio, double interval, double start,
+                DevActionHandler * hdl, DevActionMatch * matchFunc,
+                DevKillActionData * killFunc, DevInfoFunc * infoFunc);
+                
+/** \brief Schedule a periodic action, without specified start
+ *
+ * Parameters see DevScheduleS.
+ */
 int DevSchedule(DevSer * devser, void *actionData,
                 DevPrio prio, double interval,
                 DevActionHandler * hdl, DevActionMatch * matchFunc,