diff --git a/features/esm_SAM.py b/features/esm_SAM.py
index e4c5adc..1f30ed6 100644
--- a/features/esm_SAM.py
+++ b/features/esm_SAM.py
@@ -55,6 +55,15 @@ def extract_stressful_events(df_esm: pd.DataFrame) -> pd.DataFrame:
         )
     )
 
+    # 4.
+    df_esm_event_duration = extract_event_duration(df_esm_sam_clean)
+
+    df_esm_events = df_esm_events.join(
+        df_esm_event_duration[
+            GROUP_QUESTIONNAIRES_BY + ["event_duration", "event_duration_info"]
+        ].set_index(GROUP_QUESTIONNAIRES_BY)
+    )
+
     return df_esm_events
 
 
@@ -118,3 +127,36 @@ def convert_event_time(df_esm_sam_clean: pd.DataFrame) -> pd.DataFrame:
         )
     )
     return df_esm_event_time
+
+
+def extract_event_duration(df_esm_sam_clean: pd.DataFrame) -> pd.DataFrame:
+    df_esm_event_duration = df_esm_sam_clean[
+        df_esm_sam_clean["questionnaire_id"]
+        == QUESTIONNAIRE_ID_SAM.get("event_duration")
+    ].assign(
+        event_duration=lambda x: pd.to_datetime(
+            x.esm_user_answer.str.slice(start=0, stop=-6), errors="coerce"
+        ).dt.time
+    )
+    # TODO Explore the values recorded in event_duration and possibly fix mistakes.
+    # For example, participants reported setting 23:50:00 instead of 00:50:00.
+
+    # For the events that no duration was found (i.e. event_duration = NaT),
+    # we can determine whether:
+    #   - this event is still going on ("1 - It is still going on")
+    #   - the participant couldn't remember it's duration ("0 - I do not remember")
+    # Generally, these answers were converted to esm_user_answer_numeric in clean_up_esm,
+    # but only the numeric types of questions and answers.
+    # Since this was of "datetime" type, convert these specific answers here again.
+    df_esm_event_duration[
+        df_esm_event_duration.event_duration.isna()
+    ] = df_esm_event_duration[df_esm_event_duration.event_duration.isna()].assign(
+        event_duration_info=lambda x: x.esm_user_answer.str.slice(stop=1).astype(
+            int
+        )
+    )
+
+    return df_esm_event_duration
+
+
+# TODO: How many questions about the stressfulness of the period were asked and how does this relate to events?