from qiskit import pulse

d0 = pulse.DriveChannel(0)
d1 = pulse.DriveChannel(1)

with pulse.build() as pulse_prog:
    with pulse.align_right():
        # this pulse will start at t=0
        pulse.play(pulse.Constant(100, 1.0), d0)
        # this pulse will start at t=80
        pulse.play(pulse.Constant(20, 1.0), d1)

pulse_prog.draw()