Use datetime.isoformat() to send eta, and dateutil.parse.parse to receive eta.

celery/messaging.py

@@ -46,6 +46,8 @@ class TaskPublisher(Publisher):
         """INTERNAL"""
 
         task_id = task_id or gen_unique_id()
+        eta = kwargs.get("eta")
+        eta = eta and eta.isoformat()
 
         message_data = {
             "task": task_name,
@@ -53,7 +55,7 @@ class TaskPublisher(Publisher):
             "args": task_args or [],
             "kwargs": task_kwargs or {},
             "retries": kwargs.get("retries", 0),
-            "eta": kwargs.get("eta"),
+            "eta": eta,
         }
 
         if part_of_set:

celery/worker/__init__.py

@@ -8,6 +8,7 @@ import logging
 import socket
 from Queue import Queue
 
+import dateutil
 from carrot.connection import DjangoBrokerConnection, AMQPConnectionException
 
 from celery import conf
@@ -106,6 +107,7 @@ class CarrotListener(object):
 
         eta = message_data.get("eta")
         if eta:
+            eta = dateutil.parser.parse(eta)
             self.prefetch_count.increment()
             self.logger.info("Got task from broker: %s[%s] eta:[%s]" % (
                     task.task_name, task.task_id, eta))