Fix end data issue

app.py

@@ -4,20 +4,18 @@ from datetime import datetime, timedelta, date
 # Title of the application
 st.title('Smart Travel Itinerary Suggester')
 
-# Initialize session state for start_date and end_date if not present
+# Callback function to update the end date
+def update_end_date():
+    if st.session_state.end_date <= st.session_state.start_date:
+        # Update the end date in session state to be one day after the start date
+        st.session_state.end_date = st.session_state.start_date + timedelta(days=1)
+
+# Set default values for start_date and end_date in session state if not already set
 if 'start_date' not in st.session_state:
     st.session_state['start_date'] = datetime.today()
 
 if 'end_date' not in st.session_state:
-    st.session_state['end_date'] = datetime.today() + timedelta(days=1)
-
-
-def update_end_date():
-    # Only update end_date if it is not None and the start_date is equal to or after the current end_date
-    if 'end_date' in st.session_state and st.session_state['end_date'] is not None:
-        if st.session_state['start_date'] >= st.session_state['end_date']:
-            # Set the end_date in the session state to one day after the new start_date
-            st.session_state['end_date'] = st.session_state['start_date'] + timedelta(days=1)
+    st.session_state['end_date'] = st.session_state['start_date'] + timedelta(days=1)
 
 # Sidebar for input
 with st.sidebar:
@@ -29,13 +27,13 @@ with st.sidebar:
     # Travel Dates input
     today = date.today()
 
-    # Travel Dates input
+    # Create the start date input widget
     start_date = st.date_input(
-        'Start Date',
-        value=st.session_state['start_date'],
-        min_value=datetime.today(),
-        key='start_date',
-        on_change=update_end_date
+    'Start Date',
+    min_value=datetime.today(),
+    value=st.session_state.start_date,
+    key='start_date',  # Link this widget to the start_date in session state
+    on_change=update_end_date  # Callback function to call when this date input changes
     )
 
     end_date = st.date_input(
@@ -46,9 +44,13 @@ with st.sidebar:
         help='End Date must be after the Start Date.'
     )
 
-    # Synchronize state
-    st.session_state['start_date'] = start_date
-    st.session_state['end_date'] = end_date
+    # Create the end date input widget
+    end_date = st.date_input(
+        'End Date',
+        min_value=st.session_state.start_date + timedelta(days=1),
+        value=st.session_state.end_date,
+        key='end_date'  # Link this widget to the end_date in session state
+    )
 
     # Preferences multiselect
     attractions = st.multiselect(