def get_mode_endpoints(t1, t2, t3, t4):
    """Compute cumulative time in inflexibility profile for each mode endpoint"""

    # Time interval endpoints
    t1_end = t1
    t2_end = t1 + t2
    t3_end = t1 + t2 + t3
    t4_end = t1 + t2 + t3 + t4

    return t1_end, t2_end, t3_end, t4_end