> For the complete documentation index, see [llms.txt](https://cvnnt.gitbook.io/documentation/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cvnnt.gitbook.io/documentation/system-architecture/governance/system-nodes/node-rotation/epoch-overlap.md).

# Epoch overlap

Epoch overlap is an intersection of epochs (current and next master node groups).

Epochs in Covenant system validation and cross-chain messaging verification mechanics are overlapped, during the overlap two validation groups are presented at the same time. Epoch overlap reduces verification process centralization risks for Collator and Validator master node sets as it provides technical inability for a particular master node to participate in validation processes two Epochs in a row as the node participating in current validation activity round during a particular Epoch can not nominate for the next round.

Epoch overlap serves several goals:

* To explicitly ensure a node can't participate in validation process two times in a row;
* For sweep transactions protocol implementation (validation power transition from current node group to the next group);