diff --git a/pm4py/objects/conversion/log/variants/to_nx.py b/pm4py/objects/conversion/log/variants/to_nx.py
index 171336437..d7a2d18c7 100644
--- a/pm4py/objects/conversion/log/variants/to_nx.py
+++ b/pm4py/objects/conversion/log/variants/to_nx.py
@@ -63,6 +63,8 @@ def apply(log_obj: Union[EventLog, EventStream, pd.DataFrame], parameters: Optio
     case_id_attribute = exec_utils.get_param_value(Parameters.CASE_ID_ATTRIBUTE, parameters, "concept:name")
     other_case_attributes_as_nodes = exec_utils.get_param_value(Parameters.OTHER_CASE_ATTRIBUTES_AS_NODES, parameters, None)
     event_attributes_as_nodes = exec_utils.get_param_value(Parameters.EVENT_ATTRIBUTES_AS_NODES, parameters, None)
+
+    parameters["stream_postprocessing"] = True
     log_obj = to_event_log.apply(log_obj, parameters=parameters)
 
     if event_attributes_as_nodes is None:
diff --git a/pm4py/objects/conversion/ocel/variants/ocel_to_nx.py b/pm4py/objects/conversion/ocel/variants/ocel_to_nx.py
index e8637ac43..bf9ef6bc6 100644
--- a/pm4py/objects/conversion/ocel/variants/ocel_to_nx.py
+++ b/pm4py/objects/conversion/ocel/variants/ocel_to_nx.py
@@ -20,6 +20,8 @@
 import networkx as nx
 from typing import Optional, Dict, Any
 from pm4py.util import exec_utils
+from pm4py.objects.conversion.log.variants import to_event_stream
+from copy import copy
 
 
 class Parameters(Enum):
@@ -57,13 +59,15 @@ def apply(ocel: OCEL, parameters: Optional[Dict[Any, Any]] = None) -> nx.DiGraph
     G = nx.DiGraph()
 
     stream = ocel.events.to_dict("records")
+    stream = to_event_stream.__postprocess_stream(stream)
     for ev in stream:
-        ev["type"] = "event"
+        ev["type"] = "EVENT"
         G.add_node(ev[ocel.event_id_column], attr=ev)
 
     stream = ocel.objects.to_dict("records")
+    stream = to_event_stream.__postprocess_stream(stream)
     for obj in stream:
-        obj["type"] = "object"
+        obj["type"] = "OBJECT"
         G.add_node(obj[ocel.object_id_column], attr=obj)
 
     rel_cols = {ocel.event_id_column, ocel.object_id_column, ocel.qualifier}
@@ -96,7 +100,9 @@ def apply(ocel: OCEL, parameters: Optional[Dict[Any, Any]] = None) -> nx.DiGraph
         object_changes = ocel.object_changes.to_dict("records")
         for i in range(len(object_changes)):
             change_id = "@@change##%d" % i
-            G.add_node(change_id, attr=object_changes[i])
-            G.add_edge(object_changes[i][ocel.object_id_column], change_id)
+            change_dict = copy(object_changes[i])
+            change_dict["type"] = "CHANGE"
+            G.add_node(change_id, attr=change_dict)
+            G.add_edge(change_id, object_changes[i][ocel.object_id_column])
 
     return G
diff --git a/pm4py/util/pandas_utils.py b/pm4py/util/pandas_utils.py
index 4811638a6..59695c863 100644
--- a/pm4py/util/pandas_utils.py
+++ b/pm4py/util/pandas_utils.py
@@ -258,7 +258,7 @@ def check_is_pandas_dataframe(log):
     return type(log) is pd.DataFrame
 
 
-def check_pandas_dataframe_columns(df, activity_key=None, case_id_key=None, timestamp_key=None):
+def check_pandas_dataframe_columns(df, activity_key=None, case_id_key=None, timestamp_key=None, start_timestamp_key=None):
     """
     Checks if the dataframe contains all the required columns.
     If not, raise an exception
@@ -310,6 +310,16 @@ def check_pandas_dataframe_columns(df, activity_key=None, case_id_key=None, time
         if df[timestamp_key].isnull().values.any():
             raise Exception("the timestamp column should not contain any empty value.")
 
+    if start_timestamp_key is not None:
+        if start_timestamp_key not in df.columns:
+            raise Exception("the specified start timestamp column is not contained in the dataframe. Available columns: "+str(sorted(list(df.columns))))
+
+        if start_timestamp_key not in timest_columns:
+            raise Exception("the start timestamp column should be of time datetime. Use the function pandas.to_datetime")
+
+        if df[start_timestamp_key].isnull().values.any():
+            raise Exception("the start timestamp column should not contain any empty value.")
+
     """if len(set(df.columns).intersection(
             set([constants.CASE_CONCEPT_NAME, xes_constants.DEFAULT_NAME_KEY,
                  xes_constants.DEFAULT_TIMESTAMP_KEY]))) < 3:
diff --git a/pm4py/utils.py b/pm4py/utils.py
index be84fc07a..87eb39859 100644
--- a/pm4py/utils.py
+++ b/pm4py/utils.py
@@ -293,13 +293,14 @@ def deserialize(ser_obj: Tuple[str, bytes]) -> Any:
         return dfg_importer.deserialize(ser_obj[1])
 
 
-def get_properties(log, activity_key: str = "concept:name", timestamp_key: str = "time:timestamp", case_id_key: str = "case:concept:name", resource_key: str = "org:resource", group_key: Optional[str] = None, **kwargs):
+def get_properties(log, activity_key: str = "concept:name", timestamp_key: str = "time:timestamp", case_id_key: str = "case:concept:name", resource_key: str = "org:resource", group_key: Optional[str] = None, start_timestamp_key: Optional[str] = None, **kwargs):
     """
     Gets the properties from a log object
 
     :param log: Log object
     :param activity_key: attribute to be used for the activity
     :param timestamp_key: attribute to be used for the timestamp
+    :param start_timestamp_key: (optional) attribute to be used for the start timestamp
     :param case_id_key: attribute to be used as case identifier
     :param resource_key: (if provided) attribute to be used as resource
     :param group_key: (if provided) attribute to be used as group identifier
@@ -320,6 +321,9 @@ def get_properties(log, activity_key: str = "concept:name", timestamp_key: str =
     if timestamp_key is not None:
         parameters[constants.PARAMETER_CONSTANT_TIMESTAMP_KEY] = timestamp_key
 
+    if start_timestamp_key is not None:
+        parameters[constants.PARAMETER_CONSTANT_START_TIMESTAMP_KEY] = start_timestamp_key
+
     if case_id_key is not None:
         parameters[constants.PARAMETER_CONSTANT_CASEID_KEY] = case_id_key