add timestamp to models

hiro_models/model_base.py

@@ -17,6 +17,7 @@ from hopsflow.util import EnsembleValue
 import hashlib
 import hops.core.hierarchy_parameters as params
 from collections.abc import Callable
+from datetime import datetime
 
 
 @dataclass
@@ -43,7 +44,14 @@ class Model(ABC):
     breaking changes.
     """
 
-    _ignored_keys: list[str] = field(default_factory=lambda: ["_sigmas", "description"])
+    timestamp: datetime = field(default_factory=lambda: datetime.now())
+    """
+    A timestamp that signals when the simulation was run. Is not used to hash or compare objects.
+    """
+
+    _ignored_keys: list[str] = field(
+        default_factory=lambda: ["_sigmas", "description", "timestamp"]
+    )
     """Keys that are ignored when comparing or hashing models."""
 
     ###########################################################################

hiro_models/otto_cycle.py

@@ -173,7 +173,7 @@ class OttoEngine(QubitModelMutliBath):
     """The smoothness of the modulation of ``H``."""
 
     timings_L: tuple[Timings, Timings] = field(
-        default_factory=lambda: ((0, 0.05, 0.15, 0.2), (0.5, 0.55, 0.65, 0.7))
+        default_factory=lambda: ((0.0, 0.05, 0.15, 0.2), (0.5, 0.55, 0.65, 0.7))
     )
     """The timings for the ``L`` modulation. See :any:`SmoothlyInterpolatdPeriodicMatrix`."""
 
@@ -215,7 +215,7 @@ class OttoEngine(QubitModelMutliBath):
 
                 self.ω_s[i] = res.x
 
-        if self.t == "auto":
+        if isinstance(self.t, str) and self.t == "auto":
             t_max = self.num_cycles * self.Θ
 
             # we set this here to avoid different results on different platforms

hiro_models/utility.py

@@ -1,3 +1,5 @@
+from datetime import datetime
+import dateutil.parser
 from functools import singledispatchmethod
 import dataclasses
 from dataclasses import dataclass
@@ -96,6 +98,13 @@ class JSONEncoder(json.JSONEncoder):
             "value": obj.__getstate__(),
         }
 
+    @default.register
+    def _(self, obj: datetime):
+        return {
+            "type": "datetime",
+            "value": obj.isoformat(),
+        }
+
     @classmethod
     def dumps(cls, data, **kwargs) -> str:
         """Like :any:`json.dumps`, just for this encoder.
@@ -164,6 +173,9 @@ def object_hook(dct: dict[str, Any]):
         if type == "tuple":
             return tuple(dct["value"])
 
+        if type == "datetime":
+            return dateutil.parser.parse(dct["value"])
+
     return dct