Bitcoin block #415,000 was just mined, marking just 5,000 blocks left until block #420,000 — the point at which the mining reward will drop from it’s current bounty of 25 brand new bitcoin immediately down to 12.5.

The first bitcoin block, the so called “Genesis Block”, was mined on January 3, 2009, marking the beginning of the bitcoin “blockchain”.

The open-source bitcoin software dictates that every 210,000 blocks, the block reward will be halved, thus dubbing each such event a “Halvening”.

The reward associated with the first bitcoin block was 50 bitcoin, and as we passed block #210,000 on November 28, 2012, we watched that split down to the current reward of 25.

The bitcoin software has mechanisms in place to automatically adjust the difficulty associated with mining a new block so that a new block will be produced approximately every 10 minutes despite the level of competition (computational resources being expended on solving for the next valid block).

As we can calculate, with the “Genesis Block” occurring on January 3, 2009, block #210,000 should have occurred about 2,100,000 minutes (just under 4 years) later, around December 31, 2012.

As we can see in the blockchain, block #210,000 was actually mined about 33 days “early” on November 28, 2012.

Following this logic, we can see that we’ve crossed block #415,000 at an even quicker pace, about 171 days before the date expected after mining the “Genesis Block”.