Yes, there is a concept of epochs in the TON ecosystem as well. An epoch is a period of time during which a specific set of validators are responsible for validating transactions and creating new blocks. In TON, an epoch typically lasts for several hours, during which validators can earn rewards for successfully validating transactions.

Each epoch is composed of a fixed number of blocks, which are validated by a specific group of validators. The validators for each epoch are selected by a complex algorithm that takes into account a variety of factors, including the stake held by each validator and their previous performance in validating transactions.

Overall, the concept of epochs in the TON ecosystem is similar to that of Ethereum, in that it is a way of organizing time into discrete periods during which specific actions take place. However, the details of how epochs are implemented and managed are unique to the TON ecosystem.

You can check the related data in https://www.tonstake.com as well.