- Main page: History
- 18 – The bitcoin.org domain name is registered.
- 22 – Satoshi Nakamoto contacts Wei Dai after a referral from Adam Back.
- 31 – The Bitcoin white paper is published by Satoshi.
- 09 – The Bitcoin project is registered on SourceForge.
2009 was the year of Bitcoin's launch.
- 03 – The genesis block is established by Satoshi Nakamoto.
- 09 – Bitcoin v0.1 is released on the cryptography mailing list and mining begins.
- 11 – Block 78 is the first to be mined by a known individual other than Satoshi.
- 12 – The first transaction occurs between Satoshi and Hal Finney.
- 05 – New Liberty Standard publishes the earliest exchange rates based on cost of production.
- 12 – Satoshi releases Bitcoin v0.2.
- 30 – The difficulty adjusts for the first time, rising from 1 to 1.18 on block 32256.
Halving day 2012 (November 28, 2012) was the day of the first subsidy halving, which occurred when block 210000 was solved. Until block 420000, the block reward would be 25 BTC instead of the original 50 BTC.
At the moment before the halving, 10,500,000 BTC had been mined, 50% of the target cap.
The block was solved by a Radeon HD 5800 after mining for less than a week. This GPU would later be sold to Chaang Noi at a significant markup on August 26, 2013. Several images of the card were posted to Bitmit, but no copies are currently known to exist.