Is epoch universal?

Could you elaborate on the concept of epoch in the context of cryptocurrency and finance, and whether it is considered to be a universally accepted term or standard? I'm curious to understand if there's a consensus among experts in the field on the definition and application of epoch, or if it varies depending on the specific blockchain protocol or cryptocurrency being discussed. Additionally, I'm interested in knowing if there are any challenges or limitations associated with the use of epoch as a measurement unit in the cryptocurrency and finance industry.