The first Bitcoin transaction from Satoshi Nakamoto to Hal Finney occurred at block height 170.
On January 12, 2009, Nakamoto sent Finney 10 bitcoins, making it the first widely recognized transfer between two people on the Bitcoin network. Finney was an early cryptographer and one of the first people to download and test the Bitcoin software.
Block 170 is especially significant because the genesis block is numbered 0 and contains Bitcoin’s initial coinbase transaction, not a normal payment to another user. The transaction in block 170 therefore marks the beginning of Bitcoin’s practical peer-to-peer use.
The date can appear as January 11 in some records because the transaction’s timestamp is reported in Eastern Time; in UTC, it falls on January 12. Another common mix-up is block 9, whose mined coins were later involved in the transaction, but the payment itself was recorded in block 170.