def _reconstruct_times(clean_data):
    """Reconstruct departure_time, scheduled_dep_time,
    arrival_time and scheduled_arr_time by adding known delays
    to known times. We do:
        - dep_time is scheduled_dep + dep_delay
        - arr_time is dep_time + taxiing and air_time
        - scheduled arrival is scheduled_dep + scheduled_elapsed
    """
    clean_data.loc[:, "dep_time"] = clean_data["scheduled_dep_time"] + pd.to_timedelta(
        clean_data["dep_delay"],
        unit="m",
    )

    clean_data.loc[:, "arr_time"] = clean_data["dep_time"] + pd.to_timedelta(
        clean_data["taxi_out"] + clean_data["air_time"] + clean_data["taxi_in"],
        unit="m",
    )

    clean_data.loc[:, "scheduled_arr_time"] = (
        clean_data["scheduled_dep_time"] + clean_data["scheduled_elapsed_time"]
    )
    return clean_data
Reconstruct departure_time, scheduled_dep_time,
    arrival_time and scheduled_arr_time by adding known delays
    to known times. We do:
        - dep_time is scheduled_dep + dep_delay
        - arr_time is dep_time + taxiing and air_time
        - scheduled arrival is scheduled_dep + scheduled_elapsed
    
featuretools/demo/flight.py