Approximately how long does the shockwave take to propagate through the outer layers to create the visible supernova flash?

Answer

Several hours

For a star like a red supergiant, the shockwave generated by the core bounce requires several hours to travel through the star's outer layers and manifest as the visible light event.

Approximately how long does the shockwave take to propagate through the outer layers to create the visible supernova flash?
physicsastronomystarssupernovacore collapse