import streamlit as st
import datetime

today = datetime.date.today()
tomorrow = today + datetime.timedelta(days=1)
start_date = st.date_input('Start date', today)
end_date = st.date_input('End date', tomorrow)
if start_date < end_date:
    st.success('Start date: `%s`\n\nEnd date:`%s`' % (start_date, end_date))
else:
    st.error('Error: End date must fall after start date.')