def convert_timedelta(td):
    """ Convert a timedelta object to a timespec usable by `at`. Note that
    `at` does not understand seconds, so extra seconds are rounded down. """
    total_seconds = (td.microseconds / 1000000) + (td.days * 24 * 60 * 60) + \
        td.seconds

    total_minutes = total_seconds // 60

    plural = (abs(total_minutes) > 1)

    return 'now + {0} minute{1}'.format(total_minutes, 's' if plural else '')