Fix dt units in test util function convert_to_target

qiskit/test/mock/utils/backend_converter.py

@@ -99,7 +99,7 @@ def convert_to_target(conf_dict: dict, props_dict: dict = None, defs_dict: dict
     # parse global configuration properties
     dt = conf_dict.get("dt")
     if dt:
-        target.dt = dt
+        target.dt = dt * 1e-9
     if "timing_constraints" in conf_dict:
         target.granularity = conf_dict["timing_constraints"].get("granularity")
         target.min_length = conf_dict["timing_constraints"].get("min_length")

releasenotes/notes/fix-target-dt-4d306f1e9b07f819.yaml

@@ -0,0 +1,8 @@
+---
+fixes:
+  - |
+    Fixed an issue with :class:`~.BackendV2` based fake backend classes from the 
+    ``qiskit.providers.fake_provider`` module such as ``FakeMontrealV2`` where the
+    value for the :attr:`~.BackendV2.dt` attribute (and the :attr:`.Target.dt` attribute) 
+    were not properly being converted to seconds. This would cause issues when
+    using these fake backends with scheduling.

test/python/providers/test_fake_backends.py

@@ -103,6 +103,12 @@ def test_to_dict_properties(self, backend):
         else:
             self.assertTrue(backend.configuration().simulator)
 
+    @data(*FAKE_PROVIDER_FOR_BACKEND_V2.backends())
+    def test_convert_to_target(self, backend):
+        target = backend.target
+        if target.dt is not None:
+            self.assertLess(target.dt, 1e-6)
+
     @data(*FAKE_PROVIDER.backends())
     def test_to_dict_configuration(self, backend):
         configuration = backend.configuration()