Haikun, the author of " past, present, future:unattainable; is a zen master. true or false

True.

Haikun the author of "Past, Present, Future: Unattainable" is a Zen Master.

Explanation:

The Zen Master whose full name is Hakuin Zenji was born in Sugiyama Iwajiro, a small Japanese coastal village at the foot of Mt. Fuji.

The poem in question is:

"Past, present, future: unattainable,

Yet clear as the moteless sky.

Late at night the stool's cold as iron,

But the moonlit window smells of plum".

Cheers!

true is what the question is