from datetime import datetime


def timestamp_ddmmyyyyhhmmss_to_ntp(timestamp_str):
    """
    Converts a timestamp string, in the DD Mon YYYY HH:MM:SS format, to NTP time.
    :param timestamp_str: a timestamp string in the format DD Mon YYYY HH:MM:SS
    :return: Time (float64) in seconds from epoch 01-01-1900.
    """
    timestamp = datetime.strptime(timestamp_str, "%d %b %Y %H:%M:%S")
    return (timestamp - datetime(1900, 1, 1)).total_seconds()