def TourTypeDayShift_idx_rule(M):
    """
    Index is (start window, tour type, shift length, day, week)

    :param M: Model
    :return: Constraint index (list of tuples)
    """

    return [(i, t, k, j, w) for i in M.WINDOWS
            for t in M.activeTT
            for k in M.tt_length_x[t]
            for j in M.DAYS
            for w in M.WEEKS
            if (i, t, k, j) in M.okTourTypeDayShift]