diff --git a/a8/xtimer.cc b/a8/xtimer.cc
index a1c5dec..b8fcff8 100644
--- a/a8/xtimer.cc
+++ b/a8/xtimer.cc
@@ -342,6 +342,18 @@ namespace a8
             InternalDelete(base_->running_timer, false, true);
         }
 
+        long long GetIdleTime()
+        {
+            int idle_time = 1;
+            for (int lv1_idx = base_->timer_tick & TVR_MASK; lv1_idx < TVR_SIZE; ++lv1_idx) {
+                if (!list_empty(base_->tv1.vec + lv1_idx)) {
+                    return idle_time <= 1 ? 1 : idle_time - 1;
+                }
+                ++idle_time;
+            }
+            return idle_time <= 1 ? 1 : idle_time - 1;
+        }
+
     private:
 
         void AddToFreeList(xtimer_list* timer)
@@ -574,4 +586,9 @@ namespace a8
         impl_->DeleteCurrentTimer();
     }
 
+    long long XTimer::GetIdleTime()
+    {
+        return impl_->GetIdleTime();
+    }
+
 }
diff --git a/a8/xtimer.h b/a8/xtimer.h
index 4fbf377..63277b5 100644
--- a/a8/xtimer.h
+++ b/a8/xtimer.h
@@ -32,6 +32,7 @@ namespace a8
         long long GetRemainTime(XTimerWp& timer_wp);
         void DeleteCurrentTimer();
         bool IsRunning();
+        long long GetIdleTime();
 
     private:
         void ClearAttacher(Attacher* attacher);