def series_to_json_obj(ts):
    """
    Returns a dictionary of values in DeepAR, JSON format.
       :param ts: A single time series.
       :return: A dictionary of values with "start" and "target" keys.
    """
    
    # get start time and target from the time series, ts
    json_obj = {"start": str(ts.index[0]), "target": list(ts)}
    return json_obj