diff --git a/qlib/workflow/task/gen.py b/qlib/workflow/task/gen.py
index 1d363d7f1..c64939e82 100644
--- a/qlib/workflow/task/gen.py
+++ b/qlib/workflow/task/gen.py
@@ -36,14 +36,13 @@ def task_generator(tasks, generators) -> list:
         generators = [generators]
 
     # generate gen_task_list
-    gen_task_list = []
     for gen in generators:
         new_task_list = []
         for task in tasks:
             new_task_list.extend(gen.generate(task))
-        gen_task_list = new_task_list
+        tasks = new_task_list
 
-    return gen_task_list
+    return tasks
 
 
 class TaskGen(metaclass=abc.ABCMeta):
diff --git a/qlib/workflow/task/utils.py b/qlib/workflow/task/utils.py
index 15123a291..29d7a495c 100644
--- a/qlib/workflow/task/utils.py
+++ b/qlib/workflow/task/utils.py
@@ -30,6 +30,7 @@ def get_mongodb():
     client = MongoClient(cfg["task_url"])
     return client.get_database(name=cfg["task_db_name"])
 
+
 def list_recorders(experiment, rec_filter_func=None):
     """list all recorders which can pass the filter in a experiment.
 
@@ -50,6 +51,7 @@ def list_recorders(experiment, rec_filter_func=None):
 
     return recs_flt
 
+
 class TimeAdjuster:
     """
     find appropriate date and adjust date.
@@ -146,7 +148,7 @@ class TimeAdjuster:
         """
         if isinstance(segment, dict):
             return {k: self.align_seg(seg) for k, seg in segment.items()}
-        elif isinstance(segment, tuple):
+        elif isinstance(segment, tuple) or isinstance(segment, list):
             return self.align_time(segment[0], tp_type="start"), self.align_time(segment[1], tp_type="end")
         else:
             raise NotImplementedError(f"This type of input is not supported")