An epoch is just any given time period usually marked by specific events. For example, one might describe the period of the French Revolution as "the epoch of belief,...the epoch of incredulity"...
Epoch, the geologic time period which is shorter than period but longer than an age
an extended period of time -love - from mahayla
The current epoch is the Holocene. It began about 11,700 years ago.
How long is an epoch? Longer than an era but shorter than an age of course!