Backfill start_date to override the tasks's start_date

airflow/bin/cli.py

@@ -100,6 +100,10 @@ def run(args):
         dag = dag_pickle.pickle
         task = dag.get_task(task_id=args.task_id)
 
+    task_start_date = None
+    if args.task_start_date:
+        task_start_date = dateutil.parser.parse(args.task_start_date)
+        task.start_date = task_start_date
     ti = TaskInstance(task, args.execution_date)
 
     if args.local:
@@ -109,6 +113,7 @@ def run(args):
             mark_success=args.mark_success,
             force=args.force,
             pickle_id=args.pickle,
+            task_start_date=task_start_date,
             ignore_dependencies=args.ignore_dependencies)
         run_job.run()
     elif args.raw:
@@ -394,6 +399,9 @@ def get_parser():
     parser_run.add_argument(
         "-sd", "--subdir", help=subdir_help,
         default=DAGS_FOLDER)
+    parser_run.add_argument(
+        "-s", "--task_start_date",
+        help="Override the tasks's start_date (used internally)",)
     parser_run.add_argument(
         "-m", "--mark_success", help=mark_success_help, action="store_true")
     parser_run.add_argument(

airflow/executors/base_executor.py

@@ -36,12 +36,13 @@ def queue_command(self, key, command, priority=1, queue=None):
 
     def queue_task_instance(
             self, task_instance, mark_success=False, pickle_id=None,
-            force=False, ignore_dependencies=False):
+            force=False, ignore_dependencies=False, task_start_date=None):
         command = task_instance.command(
             local=True,
             mark_success=mark_success,
             force=force,
             ignore_dependencies=ignore_dependencies,
+            task_start_date=task_start_date,
             pickle_id=pickle_id)
         self.queue_command(
             task_instance.key,

airflow/jobs.py

@@ -508,6 +508,7 @@ def _execute(self):
                     executor.queue_task_instance(
                         ti,
                         mark_success=self.mark_success,
+                        task_start_date=self.bf_start_date,
                         pickle_id=pickle_id)
                     ti.state = State.RUNNING
                     if key not in started:
@@ -556,12 +557,14 @@ def __init__(
             force=False,
             mark_success=False,
             pickle_id=None,
+            task_start_date=None,
             *args, **kwargs):
         self.task_instance = task_instance
         self.ignore_dependencies = ignore_dependencies
         self.force = force
         self.pickle_id = pickle_id
         self.mark_success = mark_success
+        self.task_start_date = task_start_date
         super(LocalTaskJob, self).__init__(*args, **kwargs)
 
     def _execute(self):
@@ -571,6 +574,7 @@ def _execute(self):
             force=self.force,
             pickle_id=self.pickle_id,
             mark_success=self.mark_success,
+            task_start_date=self.task_start_date,
             job_id=self.id,
         )
         self.process = subprocess.Popen(['bash', '-c', command])

airflow/models.py

@@ -411,6 +411,7 @@ def command(
             local=False,
             pickle_id=None,
             raw=False,
+            task_start_date=None,
             job_id=None):
         """
         Returns a command that can be executed anywhere where airflow is
@@ -424,6 +425,8 @@ def command(
         ignore_dependencies = "-i" if ignore_dependencies else ""
         force = "--force" if force else ""
         local = "--local" if local else ""
+        task_start_date = \
+            "-s " + task_start_date.isoformat()  if task_start_date else ""
         raw = "--raw" if raw else ""
         subdir = ""
         if not pickle and self.task.dag and self.task.dag.full_filepath:
@@ -439,6 +442,7 @@ def command(
             "{job_id} "
             "{raw} "
             "{subdir} "
+            "{task_start_date} "
         ).format(**locals())
 
     @property