Cardano has reached a major milestone en route to the Dijkstra era with the van Rossem hard fork initiation governance action submitted on the mainnet.
van Rossem, an intra-era hard fork, introduces some new features and lays the foundation for the next major era, Dijkstra, which will ultimately bring Leios to the Cardano mainnet.
A hard fork is one of the most visible and celebrated moments in Cardano development, but rarely is it the work of a single team or a single decision.
By the time a hard fork reaches Mainnet, it represents months of intense testing, coordination, trials and errors, governance discussions, infrastructure upgrades, and debates; hence, the submission of the van Rossem hard fork initiation governance action on the Cardano mainnet remains significant.
Van Rossem hard fork progresses
Progress towards the van Rossem hard fork on Cardano Mainnet has been continuing across the Preview and Preprod test networks throughout May and June 2026. The process primarily involved two governance actions: a Plutus Cost Model (PCM) parameter update action and a hard fork initiation action.
The van Rossem hard fork initiation governance action has been submitted on the Cardano mainnet.
An intra-era hard fork that introduces some new features and lays the foundation for the next major era, Dijkstra, which will ultimately bring Leios to Cardano mainnet.
Looking to… pic.twitter.com/IiB3t0Akke
— Intersect (@IntersectMBO) June 16, 2026
The Plutus Cost Model parameter update was enacted on the Preview test network, which hard forked to protocol version 11 on May 8 following the Plutus Cost Model parameter update on April 17 and the release of Cardano-node-11.0.1 and db-sync-13.7.0.5 in early May. The Plutus Cost Model parameter update was enacted on the Preprod test network on May 16.
Following successful upgrades on the Preview and Preprod networks, the Plutus Cost Model parameter update action was submitted to mainnet on May 26. DReps and CC members ratified the update on June 13, with the enactment scheduled for June 18, 2026 at 21:45 UTC.
Potential key dates
Following the submission of the van Rossem hard fork initiation governance action on the Cardano mainnet, potential ratification dates are given as June 23, 28, or even July 3, 8, 13, or 18.
Potential hard fork enactment dates could come as soon as June 28 if the action passes quickly; other dates being considered are July 3, 8, 13, 18, and 23.
The van Rossem hard fork governance action on the mainnet is due to expire on July 18.
