Bitcoin calendar.
Halvings and network upgrades, the US releases that move markets, conferences, and the anniversaries of Bitcoin's history. Dates are in UTC.
In 11 days
Difficulty adjustment
NetworkThursday 12 November (estimate)
At block 975,744, mining is expected to get about 0.5% easier, so blocks keep arriving about every 10 minutes.
October 2025
| Monday | Tuesday | Wednesday | Thursday | Friday | Saturday | Sunday |
|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | ||
| 6 | 7 | 8 | 9 | 10Bitcoin Core 30.0 lifts the OP_RETURN limit | 11 | 12 |
| 13 | 14 | 15 | 16 | 17 | 18 | 19 |
| 20 | 21 | 22 | 23 | 24 | 25 | 26 |
| 27 | 28 | 29Record difficulty | 30 | 31 |
Adds the dates ahead, network only, to Apple Calendar or Outlook, and keeps them up to date. In Google Calendar, use Add to Google Calendar, or download the file.
Events in October 2025
Friday 10 October387 days ago
Bitcoin Core 30.0 lifts the OP_RETURN limit
Bitcoin Core 30.0 was released, raising the default limit on data in OP_RETURN outputs (unspendable outputs used to attach data to a transaction) from 83 bytes to 100,000 bytes, which in practice removes the cap.
NetworkSourceBitcoin Core 30.0 release notes (published October 10, 2025)
Wednesday 29 October368 days ago
Mining difficulty reaches a record
Mining difficulty, a measure of how hard it is to find a block, rose 6.3% at block 921,312 to a record of about 156 trillion. As of October 2026 it had not been higher.
Network · 10:14 UTCSee block 921,312Sourcemempool.space, block 921,312 (difficulty 155.97 trillion)