def time_print(tdiff):
    """Print time

    Helper function to print time remaining in sensible units.

    Args:
        tdiff (float): time in seconds

    Returns:
        tuple: (float time, string units)
    """
    units = 'seconds'
    if tdiff > 60:
        tdiff /= 60
        units = 'minutes'
        if tdiff > 60:
            tdiff /= 60
            units = 'hours'
            if tdiff > 24:
                tdiff /= 24
                units = 'days'
    return tdiff, units