What is the approximate lifespan of the final shedding process during the AGB phase, which leads to a white dwarf?

Answer

A few tens of thousands of years

The final stage of the AGB phase, involving the ejection of the star's outer layers to form a planetary nebula, is extremely rapid when measured cosmically, lasting perhaps only a few tens of thousands of years.

What is the approximate lifespan of the final shedding process during the AGB phase, which leads to a white dwarf?
astronomylifespanstarred giantstar evolution