Part 4: Upgrades

Phase 0

For historical reasons, the initial configuration of the beacon chain at its genesis was called Phase 0.

Beacon chain genesis took place at 12:00:23 UTC on the 1st of December 2020. The extra 23 seconds comes from the timestamp of the first Eth1 block to meet the genesis criteria, block 11320899. It is a little remnant of proof of work forever embedded in the beacon chain's history.

See the Phase 0 specs for the full description. These specs still apply to the beacon chain today, except where they were superseded by the Altair, Bellatrix, or later upgrades.

My Phase 0 annotated specification remains available.