Network upgrade 2027Bitcoin Cash yearly upgrade, 15 May
Bitcoin Cash upgrades its rules at most once a year, on 15 May. The activation time for 2027 is written in the node software.
Activation
- Rule
- median time past ≥ 1,810,382,400
- Median time past now
- no data yet
- Time left on the chain's clock
- no data yet
- Status in the node source
- tentative
Source: Bitcoin Cash Node, chainparams.cpp (upgrade2027ActivationTime).
Past May upgrades
| Year | First block with new rules | Main changes |
|---|---|---|
| 15 May 2023 | 792,773 | CashTokens, P2SH32 |
| 15 May 2024 | 845,891 | Adaptive blocksize limit (ABLA) |
| 15 May 2025 | 898,374 | VM limits, BigInt |
| 15 May 2026 | 951,145 | — |
Activation blocks are taken from the node source. The list of proposals (CHIPs) for 2027 is not shown here until it is part of a released node version.
Questions
When does the 2027 upgrade activate?
The node software uses a time rule: the first block whose previous block has a median time past of 15 May 2027, 12:00:00 UTC or later is the first block under the new rules. Median time past runs about an hour behind the clock, so the activation block is usually mined around 13:00 UTC.
Is the 2027 upgrade final?
In the Bitcoin Cash Node source the 15 May 2027 time is marked as tentative. This page shows the value from the software and does not list proposals as included before they are part of a released node version.
Does an upgrade change the halving?
No. The halving is fixed at block 1,050,000 and no yearly upgrade has changed the issuance schedule.
What is median time past?
The median of the time stamps of the last eleven blocks. Consensus rules use it instead of a single block's time stamp because one miner cannot move it much.