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Encyclopedia How the network works · Entry 92

Bitcoin timelocks: absolute dates and relative waiting periods

AI-assisted research · separate automated verificationCorrections

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How the network works
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5 cited records
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Key facts

Key facts for Bitcoin timelocks: absolute dates and relative waiting periods
FactDetailSource
AbsoluteCHECKLOCKTIMEVERIFY can enforce an absolute transaction locktime condition.[1]
RelativeSequence-based locks can measure block age or time in 512-second units.[2]
Script pathCHECKSEQUENCEVERIFY can require a relative-lock condition in a script.[3]
01

A date-like condition versus an elapsed-age condition

An absolute height condition refers to the same chain height regardless of when the output was created. A relative block lock starts from the confirmation height of the particular output being spent.

For example, a relative delay of 144 blocks is about confirmation age, not a guaranteed 24-hour wall-clock wait. Block intervals vary, and time-based rules use specified chain-time measurements.

02

Unlocking time is not spending authority

A script can combine a timing condition with a signature requirement or provide several spending branches. Reaching one branch’s time threshold does not eliminate the other requirements of that branch.

A wallet-local “locked coin” setting is different: it can exclude a coin from automatic selection without imposing a consensus restriction on other holders of the signing keys.

03

Budget for the transaction that comes afterward

After a valid spending path becomes available, someone still needs to construct and submit the transaction and pay its fee. Inclusion depends on the network and miner selection.

Read the exact script and locktime semantics rather than treating a countdown in an interface as a promise of immediate delivery.

Direct answers

Questions people ask

Can a timelock send funds automatically on a calendar date?

A timelock alone cannot initiate a payment. It changes validity conditions; an authorized party still has to create and submit a valid spending transaction.

Inspect the evidence

The answer and key facts have stable claim links. These records retain the scope and qualification when reused.

A Bitcoin timelock restricts when a transaction or spending path can be valid. Absolute locks refer to a block height or time condition; relative locks depend on an input’s confirmation age. Reaching the condition permits an otherwise valid spend—it does not automatically broadcast, sign or confirm a payment.

Scope: Bitcoin · data through 2026-10-02. Verification: verified · 2026-10-02T18:15:23.891Z.

Link to this claim
Absolute: CHECKLOCKTIMEVERIFY can enforce an absolute transaction locktime condition.

Scope: Bitcoin · data through 2026-10-02. Verification: verified · 2026-10-02T18:15:23.891Z.

Link to this claim
Relative: Sequence-based locks can measure block age or time in 512-second units.

Scope: Bitcoin · data through 2026-10-02. Verification: verified · 2026-10-02T18:15:23.891Z.

Link to this claim
Script path: CHECKSEQUENCEVERIFY can require a relative-lock condition in a script.

Scope: Bitcoin · data through 2026-10-02. Verification: verified · 2026-10-02T18:15:23.891Z.

Link to this claim
Revision history
  1. — Initial Bitcoin encyclopedia entry at this permanent URL.
  2. — Added reusable claims, explicit source locators, and matching Markdown and JSON. This publishing change does not itself establish factual verification.

Source register

Sources and references

Retrieval dates and locators are recorded individually.
  1. OP_CHECKLOCKTIMEVERIFYBitcoin BIPs contributors

    Absolute locktime constraints for spending transaction outputs.

    Locator: Summary; Specification · Version / scope: BIP-65; immutable revision pinned in source URL · Retrieved: 2026-10-02T17:22:20.600ZOpen source
  2. Relative lock-time using consensus-enforced sequence numbersBitcoin BIPs contributors

    Sequence-based relative confirmation age constraints.

    Locator: Specification · Version / scope: BIP-68; immutable revision pinned in source URL · Retrieved: 2026-10-02T17:22:20.762ZOpen source
  3. CHECKSEQUENCEVERIFYBitcoin BIPs contributors

    Script enforcement of relative lock-time constraints.

    Locator: Summary; Specification · Version / scope: BIP-112; immutable revision pinned in source URL · Retrieved: 2026-10-02T17:22:20.748ZOpen source
  4. lockunspent RPCBitcoin Core

    Preventing specified wallet outputs from automatic coin selection.

    Locator: Arguments and result fields · Version / scope: Bitcoin Core 29.0.0 RPC · Retrieved: 2026-10-02T17:03:41.086ZOpen source
  5. Bitcoin Developer Guide: TransactionsBitcoin developer documentation contributors

    UTXO inputs, transaction outputs, change and the difference paid as a fee.

    Locator: P2PKH Script Validation; Transaction Fees And Change · Retrieved: 2026-10-02T17:03:41.190ZOpen source
How this article was made

Research and drafting use AI assistance. A separate automated review checks claims against primary sources; no external expert or named human review is implied. Publication, substantive editing, source retrieval and verification are recorded separately. This version was independently checked by an automated reviewer on 2 October 2026.

Editorial method and corrections

Degrees of Satoshi editorial project. “Bitcoin timelocks: absolute dates and relative waiting periods.” Published 2026-10-02; updated 2026-10-02. https://degreesofsatoshi.com/encyclopedia/bitcoin-timelocks/