diff --git a/pyphare/pyphare/pharein/__init__.py b/pyphare/pyphare/pharein/__init__.py
index 5704efb49..71ad6c5e0 100644
--- a/pyphare/pyphare/pharein/__init__.py
+++ b/pyphare/pyphare/pharein/__init__.py
@@ -365,7 +365,7 @@ def as_paths(rb):
         if "dir" in restart_options:
             restart_file_path = restart_options["dir"]
 
-        if "restart_time" in restart_options and restart_options["restart_time"] > 0:
+        if "restart_time" in restart_options:
             from pyphare.cpp import cpp_etc_lib
 
             restart_time = restart_options["restart_time"]
diff --git a/pyphare/pyphare/pharein/simulation.py b/pyphare/pyphare/pharein/simulation.py
index b0db542b3..6e71cd0b2 100644
--- a/pyphare/pyphare/pharein/simulation.py
+++ b/pyphare/pyphare/pharein/simulation.py
@@ -531,9 +531,10 @@ def check_restart_options(**kwargs):
         "restart_time",  # number or "auto"
         "keep_last",  # delete obsolete
     ]
-    restart_options = kwargs.get("restart_options", None)
 
-    if restart_options is not None:
+    restart_options = kwargs.get("restart_options", {})
+
+    if "restart_options" in kwargs:
         for key in restart_options.keys():
             if key not in valid_keys:
                 raise ValueError(
@@ -553,8 +554,11 @@ def check_restart_options(**kwargs):
                 f"Invalid restart mode {mode}, valid modes are {valid_modes}"
             )
 
-        if restart_time := restarts.restart_time(restart_options):
+        restart_time = restarts.restart_time(restart_options)
+        if restart_time is not None:
             restart_options["restart_time"] = restart_time
+        elif "restart_time" in restart_options:
+            restart_options.pop("restart_time")  # auto with no existing file to use
 
     return restart_options
 
@@ -650,7 +654,7 @@ def check_clustering(**kwargs):
 
 
 def checker(func):
-    def wrapper(simulation_object, **kwargs):
+    def wrapper(simulation_object, **kwargs_in):
         accepted_keywords = [
             "domain_size",
             "cells",
@@ -684,6 +688,7 @@ def wrapper(simulation_object, **kwargs):
             "write_reports",
         ]
 
+        kwargs = deepcopy(kwargs_in)  # local copy - dictionaries are weird
         accepted_keywords += check_optional_keywords(**kwargs)
 
         wrong_kwds = phare_utilities.not_in_keywords_list(accepted_keywords, **kwargs)
@@ -702,6 +707,7 @@ def wrapper(simulation_object, **kwargs):
 
         kwargs["clustering"] = check_clustering(**kwargs)
 
+        kwargs["restart_options"] = check_restart_options(**kwargs)
         time_step_nbr, time_step, final_time = check_time(**kwargs)
         kwargs["time_step_nbr"] = time_step_nbr
         kwargs["time_step"] = time_step
@@ -716,7 +722,6 @@ def wrapper(simulation_object, **kwargs):
 
         ndim = compute_dimension(cells)
         kwargs["diag_options"] = check_diag_options(**kwargs)
-        kwargs["restart_options"] = check_restart_options(**kwargs)
 
         kwargs["boundary_types"] = check_boundaries(ndim, **kwargs)
 
@@ -1022,9 +1027,9 @@ def start_time(self):
         return 0
 
     def is_from_restart(self):
-        return (
-            self.restart_options is not None and "restart_time" in self.restart_options
-        )
+        if self.restart_options is not None and "restart_time" in self.restart_options:
+            return self.restart_options["restart_time"] is not None
+        return False
 
     def __getattr__(
         self, name
diff --git a/src/simulator/simulator.hpp b/src/simulator/simulator.hpp
index 5883d4912..120fa5fef 100644
--- a/src/simulator/simulator.hpp
+++ b/src/simulator/simulator.hpp
@@ -359,6 +359,7 @@ Simulator<opts>::Simulator(PHARE::initializer::PHAREDict const& dict,
 {
     resman_ptr   = std::make_shared<ResourceManager_t>();
     currentTime_ = restart_time(dict);
+    finalTime_ += currentTime_; // final time is from timestep * timestep_nbr!
 
     if (dict["simulation"].contains("restarts"))
         rMan = restarts::RestartsManagerResolver::make_unique(*hierarchy_, *resman_ptr,
diff --git a/tests/simulator/test_restarts.py b/tests/simulator/test_restarts.py
index e3097553b..a60018387 100644
--- a/tests/simulator/test_restarts.py
+++ b/tests/simulator/test_restarts.py
@@ -431,7 +431,7 @@ def test_advanced_restarts_options(self):
             dup(
                 dict(
                     cells=10,
-                    time_step_nbr=10,
+                    time_step_nbr=7,
                     max_nbr_levels=1,
                     refinement="tagging",
                 )
@@ -440,13 +440,13 @@ def test_advanced_restarts_options(self):
 
         simput["interp_order"] = interp
         time_step = simput["time_step"]
-        time_step_nbr = simput["time_step_nbr"]
 
-        timestamps = time_step * np.arange(time_step_nbr + 1)
+        timestamps = time_step * np.arange(simput["time_step_nbr"] + 1)
         local_out = self.unique_diag_dir_for_test_case(f"{out}/test", ndim, interp)
         simput["restart_options"]["dir"] = local_out
         simput["restart_options"]["keep_last"] = 3
         simput["restart_options"]["timestamps"] = timestamps
+        simput["restart_options"]["restart_time"] = "auto"
 
         ph.global_vars.sim = None
         ph.global_vars.sim = ph.Simulation(**simput)
@@ -454,8 +454,16 @@ def test_advanced_restarts_options(self):
         Simulator(ph.global_vars.sim).run().reset()
         self.register_diag_dir_for_cleanup(local_out)
 
+        # restarted
+        timestamps = time_step * np.arange(7, 11)
+        simput["time_step_nbr"] = 3
         simput["restart_options"]["restart_time"] = "auto"
-        self.assertEqual(0.01, ph.restarts.restart_time(simput["restart_options"]))
+        simput["restart_options"]["timestamps"] = timestamps
+        self.assertEqual(0.007, ph.restarts.restart_time(simput["restart_options"]))
+        ph.global_vars.sim = None
+        ph.global_vars.sim = ph.Simulation(**simput)
+        setup_model()
+        Simulator(ph.global_vars.sim).run().reset()
 
         dirs = []
         for path_object in Path(local_out).iterdir():
@@ -469,6 +477,8 @@ def test_advanced_restarts_options(self):
         for i, idx in enumerate(range(8, 11)):
             self.assertAlmostEqual(dirs[i], time_step * idx)
 
+        self.assertEqual(0.01, ph.restarts.restart_time(simput["restart_options"]))
+
 
 if __name__ == "__main__":
     unittest.main()