The Dencun upgrade on the Ethereum Sepolia testnet will take place at 22:51 UTC on Thursday and complete at 23:10 UTC. Sepolia is the second of three testnets running simulations through Dencun. Earlier this month, Dencun launched on the Goerli testnet but initially failed to finalize. On February 7th, Dencun will go live on its final Ethereum testnet Holesky. Afterwards, developers will sign a date to activate Dencun on the main blockchain. Testnets replicate the main blockchain and allow developers to make any changes to protocols or their decentralized applications in a low-risk environment.