def timestamp(event):
    """
    Gets the timestamp of an event retrieved from HiDRA at Petra III

    A HiDRA event usually corresponds to a single data file written by a detector. The
    creation date and time of the file is used as timestamp for the event.

    Arguments:

        event (:class:`~onda.utils.data_event.DataEvent`): an object storing the event
            data.

    Returns:

        numpy.float64: the timestamp of the event in seconds from the Epoch.
    """
    return event.framework_info['file_creation_time']
