Beat: Fixes crash when relative option enabled. Closes #1538

celery/schedules.py

@@ -45,8 +45,10 @@ class schedule(object):
         return (self.nowfun or self.app.now)()
 
     def remaining_estimate(self, last_run_at):
-        return remaining(last_run_at, self.run_every,
-                         self.maybe_make_aware(self.now()), self.relative)
+        return remaining(
+            self.maybe_make_aware(last_run_at), self.run_every,
+            self.maybe_make_aware(self.now()), self.relative,
+        )
 
     def is_due(self, last_run_at):
         """Returns tuple of two items `(is_due, next_time_to_run)`,

celery/utils/timeutils.py

@@ -188,7 +188,7 @@ def delta_resolution(dt, delta):
     args = dt.year, dt.month, dt.day, dt.hour, dt.minute, dt.second
     for res, predicate in resolutions:
         if predicate(delta) >= 1.0:
-            return datetime(*args[:res])
+            return datetime(*args[:res], tzinfo=dt.tzinfo)
     return dt