The word "epochal" means something that is very important, significant, or influential in history. It often refers to a significant event or a time period that marks a major change or turning point in the world. Full definition
The theory of epochal time states that the genesis of an actual occasion does not take place in physical (clock) time; it creates a quantum of physical time: in every act of becoming there is the becoming of something with temporal extension; but that act itself is not extensive, in the sense that it is divisible into earlier and later acts of becoming which correspond to the extensive divisibility of what has become» (PR 69/107). (religion-online.org)
We must not be confused by Whitehead's atomistic language as some of his disciples apparently are; the so - called «epochal theory of time» is atomistic only in name. (religion-online.org)
It was the expression of living realities in the world of nature, as well as a reminiscence of epochal events in the nation's history, which were by various lines of thought accepted as symbols and figures of unseen entities of human life. (religion-online.org)