[tasks] Fix initial loop execution running prematurely

discord/ext/tasks/__init__.py

@@ -584,12 +584,13 @@ class Loop(Generic[LF]):
         time_now = (
             now if now is not MISSING else datetime.datetime.now(datetime.timezone.utc).replace(microsecond=0)
         ).timetz()
+        idx = -1
         for idx, time in enumerate(self._time):
             if time >= time_now:
                 self._time_index = idx
                 break
         else:
-            self._time_index = 0
+            self._time_index = idx + 1
 
     def _get_time_parameter(
         self,