Bitcoin's first block

Genesis Block Day: 3 January

By Laksh Gandikota ·

In one paragraphGenesis Block Day is 3 January, the date carried by block 0, the first block of Bitcoin. Its timestamp is 2009-01-03 18:15:05 UTC, and its coinbase holds a newspaper headline from that day. 3 January 2027 is the 18th anniversary and falls on a Sunday. Nobody owns the day and there is no official way to mark it. Below is what the block actually contains and a few things worth doing, most of them free.

What the day marks

Satoshi Nakamoto published the Bitcoin whitepaper on 31 October 2008. A little over two months later the chain itself began with a single block, known as block 0 or the genesis block. Its header carries the timestamp 1231006505, which is 3 January 2009, 18:15:05 UTC. Every Bitcoin block since has built on it. The next one, block 1, is timestamped 9 January 2009.

The 50 BTC reward in block 0 has never moved and cannot. The genesis coinbase was never added to the software's set of spendable outputs.

The headline

Block 0 · 3 January 2009 · 18:15:05 UTC

The Times 03/Jan/2009 Chancellor on brink of second bailout for banks

000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f

That line is the front-page headline of The Times of London for 3 January 2009. Satoshi placed it in the block's coinbase transaction, 69 bytes of plain ASCII. It shows the block was not made before that date, and it is hard not to read it as a comment on the bank bailouts of that winter as well.

The long number under it is the block's hash. The ten zeros at the front are the proof of work. The rules at the time only asked for eight.

If you want the byte-level version, I wrote up exactly where the headline sits in the block.

Ways to mark it

  1. Read the whitepaper. It is nine pages and still the clearest description of the design. bitcoin.org/bitcoin.pdf.
  2. Decode block 0 yourself. The genesis block decoder lays out the header and the coinbase and re-hashes them in your browser. It is free and needs no account.
  3. Run a node, and ask it. If you run Bitcoin Core, bitcoin-cli getblockhash 0 returns the hash above, and bitcoin-cli getblock with that hash shows the block your own machine has verified everything else against.
  4. Check your keys. Since 2019 some Bitcoiners have treated 3 January as "Proof of Keys" day, an idea started by Trace Mayer: move coins you hold on an exchange to a wallet whose keys you control. This is not advice about your money, only a note that the tradition exists.
  5. Learn how the sealing works. The interactive lesson on this site lets you edit an old block and watch the chain after it break.
  6. Strike a block of your own. This is the commercial one, and it is what this site does. You write one line and a real Bitcoin ASIC mines it into a block with the same layout as block 0, to 8, 10, 11 or 12 leading zeros, from $6.99. Twelve zeros is two more than block 0 has.

What a struck block is and is not

A struck block is a standalone block in Bitcoin's format. Its proof of work is real and anyone can re-check it. It is not on Bitcoin's blockchain, it is not a coin or a token, and it has no monetary value.

There is no special Genesis Block Day edition, price or event here. The tiers on 3 January are the same as on any other day.

See the tiers Give one as a gift

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