Index: dialin/dg/events.py
===================================================================
diff -u -rd223289863a5bbb7d9f82cacca2d65b7ac3b2281 -re1a940b7549b37e616b28563e6e7c151a897054c
--- dialin/dg/events.py	(.../events.py)	(revision d223289863a5bbb7d9f82cacca2d65b7ac3b2281)
+++ dialin/dg/events.py	(.../events.py)	(revision e1a940b7549b37e616b28563e6e7c151a897054c)
@@ -21,14 +21,15 @@
 from ..protocols.CAN import DenaliChannels
 from ..utils.base import AbstractSubSystem, publish
 from datetime import datetime
-from time import strftime, localtime
+from time import localtime
 
 
 class DGEvents(AbstractSubSystem):
     """
     Dialysate Generator (DG) Dialin API sub-class for events related commands.
     """
     UNKNOWN_STATE = "UNKNOWN_PREVIOUS_STATE"
+
     def __init__(self, can_interface, logger: Logger):
         """
 
@@ -144,7 +145,7 @@
         return list_of_events
 
     @publish(["dg_events_timestamp", '_dg_event_dictionary'])
-    def _handler_events_sync(self, message,timestamp = 0.0):
+    def _handler_events_sync(self, message, timestamp=0.0):
         """
         Handles published events message
 
@@ -192,7 +193,7 @@
             else:
                 # No op mode event has been recieved before the submode event was recieved. Use broadcast messages to
                 # determine current op mode. Previous mode can not be known
-                last_op_tuple = (strftime('%Y-%m-%d %H:%M:%S.%f', localtime(self.dg_event_op_mode_timestamp)),
+                last_op_tuple = (localtime(self.dg_event_op_mode_timestamp),
                                  DGEventList.DG_EVENT_OP_MODE_CHANGE.name, DGEvents.UNKNOWN_STATE,
                                  DGOpModes(self.dg_event_op_mode).name)
             # Get the current and previous operation modes of the last tuple in the list of the sub modes
@@ -232,8 +233,12 @@
                     # previous and current do not match so in the last type (timestamp, event type, 8, 3) the prev state
                     # should be from op mode 8 and the current state should be from op mode 3
                     previous_op_mode = last_op_tuple[len(last_op_tuple) - 2]
-                    previous_sub_mode_enum_class = self._dg_op_mode_2_sub_mode[previous_op_mode]
-                    event_data_1 = previous_sub_mode_enum_class(event_data_1).name
+                    if previous_op_mode != DGEvents.UNKNOWN_STATE:
+                        previous_sub_mode_enum_class = self._dg_op_mode_2_sub_mode[previous_op_mode]
+                        event_data_1 = previous_sub_mode_enum_class(event_data_1).name
+                    # Unknown previous state. Display value instead of name.
+                    else:
+                        event_data_1 = str(event_data_1)
                     event_data_2 = current_sub_mode_enum_class(event_data_2).name
             else:
 
@@ -253,7 +258,7 @@
         self._dg_event_dictionary[event_state_name].append(event_tuple)
         self.dg_events_timestamp = timestamp
 
-    @publish(["dg_event_op_mode_timestamp","dg_event_op_mode", "dg_event_sub_mode"])
+    @publish(["dg_event_op_mode_timestamp", "dg_event_op_mode", "dg_event_sub_mode"])
     def _handler_dg_op_mode_sync(self, message, timestamp=0.0):
         """
         Handles published DG operation mode messages.  Current DG operation mode
@@ -270,4 +275,4 @@
 
         self.dg_event_op_mode = mode[0]
         self.dg_event_sub_mode = smode[0]
-        self.dg_event_op_mode_timestamp = timestamp
\ No newline at end of file
+        self.dg_event_op_mode_timestamp = timestamp
Index: dialin/hd/hd_events.py
===================================================================
diff -u -rd223289863a5bbb7d9f82cacca2d65b7ac3b2281 -re1a940b7549b37e616b28563e6e7c151a897054c
--- dialin/hd/hd_events.py	(.../hd_events.py)	(revision d223289863a5bbb7d9f82cacca2d65b7ac3b2281)
+++ dialin/hd/hd_events.py	(.../hd_events.py)	(revision e1a940b7549b37e616b28563e6e7c151a897054c)
@@ -21,7 +21,7 @@
 from ..protocols.CAN import DenaliChannels
 from ..utils.base import AbstractSubSystem, publish
 from datetime import datetime
-from time import strftime, localtime
+from time import localtime
 
 
 class HDEvents(AbstractSubSystem):
@@ -189,7 +189,7 @@
             else:
                 # No op mode event has been recieved before the submode event was recieved. Use broadcast messages to
                 # determine current op mode. Previous mode can not be known
-                last_op_tuple = (strftime('%Y-%m-%d %H:%M:%S.%f', localtime(self.hd_event_op_mode_timestamp)),
+                last_op_tuple = (localtime(self.hd_event_op_mode_timestamp),
                                  HDEventList.HD_EVENT_OP_MODE_CHANGE.name, HDEvents.UNKNOWN_STATE,
                                  HDOpModes(self.hd_event_op_mode).name)
 
@@ -230,8 +230,12 @@
                     # previous and current do not match so in the last type (timestamp, event type, 8, 3) the prev state
                     # should be from op mode 8 and the current state should be from op mode 3
                     previous_op_mode = last_op_tuple[len(last_op_tuple) - 2]
-                    previous_sub_mode_enum_class = self._hd_op_mode_2_sub_mode[previous_op_mode]
-                    event_data_1 = previous_sub_mode_enum_class(event_data_1).name
+                    if previous_op_mode != HDEvents.UNKNOWN_STATE:
+                        previous_sub_mode_enum_class = self._hd_op_mode_2_sub_mode[previous_op_mode]
+                        event_data_1 = previous_sub_mode_enum_class(event_data_1).name
+                    # Unknown previous state. Display value instead of name.
+                    else:
+                        event_data_1 = str(event_data_1)
                     event_data_2 = current_sub_mode_enum_class(event_data_2).name
             else:
 
@@ -252,7 +256,7 @@
         self.hd_event_timestamp = timestamp
 
     @publish(["hd_event_op_mode_timestamp", "hd_event_op_mode", "hd_event_sub_mode"])
-    def _handler_hd_op_mode_sync(self, message, timestamp = 0.0):
+    def _handler_hd_op_mode_sync(self, message, timestamp=0.0):
         """
         Handles published HD operation mode messages.  Current HD operation mode
         is captured for reference.
@@ -267,4 +271,4 @@
 
         self.hd_event_op_mode = mode[0]
         self.hd_event_sub_mode = smode[0]
-        self.hd_event_op_mode_timestamp = timestamp
\ No newline at end of file
+        self.hd_event_op_mode_timestamp = timestamp