The first block to follow Genesis rules was at block height #620538, at 1:35AM UTC on February 4. It was 1.84MB in size and contained 725 transactions. Curiously, its miner was listed as “unknown” on block explorers. https://whatsonchain.com/tx/4ec3b63d764558303eda720e8e51f69bbcfe81376075657313fb587306f8a9b0 https://bitcoinblocks.live/