The Epoch increases every time you change anything in your LUKS header (like when adding or removing keys, etc.).
The LUKS2 header specification states:
>
> uint64_t seqid; // sequence ID, increased on update
>
> `seqid` is a counter (sequential number) that is always increased when a new update of the header is written. The header with a higher _seqid_ is more recent and is used for recovery (if there are primary and secondary headers with different seqid, the more recent one is automatically used).
Why this is called a "sequence ID" in code and technical documentation, but uses the term "Epoch" when shown to the end user, remains a mystery.
That it is in fact the same thing, can be seen if you read the fine source, which prints seqid as Epoch:
>
> log_std(cd, "Epoch: \t%" PRIu64 "\
", hdr->seqid);
>
**tl;dr** You can safely ignore the Epoch, it is a harmless counter with no specific meaning.