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Time NFT, ERC-721 Time Extension

ERC 5007. Anders , Lance , Shrug.

ERC 5007, Time NFT, ERC-721 Time Extension. It proposes some additional functions (startTime, endTime) to help with on-chain time management.

Status in the source: Final. A reading of the public specification, not a copy of it and not a certification.

Time NFT, ERC-721 Time Extension is worth reading for the rule it actually adds: It proposes some additional functions (startTime, endTime) to help with on-chain time management.

The five-minute read

The rule

It proposes some additional functions (startTime, endTime) to help with on-chain time management.

What was already failing

A signature that does not commit to what the user saw can be replayed into a different spend, a different chain, or a different message.

What the number does not mean

The source marks this final. That is a statement about the text, not a promise that every wallet or node has shipped it.

What a builder should be able to point at

An implementation either constrains MUST, NOT, REQUIRED or it is a different design.

One action, walked through

  1. Open ERC 5007 and read the status line before the examples.
  2. Write down the rule in one sentence. A fair version of that sentence is: It proposes some additional functions (startTime, endTime) to help with on-chain time management.
  3. Name the object that changes: MUST, NOT, REQUIRED.
  4. Ask what an old client, an old contract, or an offline counterparty does. If the document is silent, the silence is part of the design.

The argument, unpacked

What the text is allowed to settle

Ethereum Request for Comment 5007 can settle the shape of Time NFT, ERC-721 Time Extension. It cannot settle whether a later client, a later fork, or a later wallet still does this.

What this page will not pretend

There is no benchmark, no adoption number, and no claim that the mechanism is safe outside the assumptions written in the source.

What has to be true

  • You are implementing ERC 5007 at the status the text itself states: Final.
  • The object that has to change is MUST, NOT, REQUIRED. A neighbouring document with a similar name is not this one.
  • Wallet support is not the same as consensus validity.

What happened after the paper

The source marks this final. That is a statement about the text, not a promise that every wallet or node has shipped it. Later documents can narrow, replace, or ignore this one. Cite the number you mean.

What to check before you use the idea

  • What is covered by the signed bytes in Time NFT, ERC-721 Time Extension?
  • Can the same signature be replayed on another chain, account, or message?
  • Which primitive does the text require: MUST, NOT, REQUIRED?

Terms

ERC 5007
The public text titled Time NFT, ERC-721 Time Extension.
Final
The document's own label for how finished the text is. It is not a market fact.

The problem the paper names

A signature that does not commit to what the user saw can be replayed into a different spend, a different chain, or a different message.

What the design proposes

  • It proposes some additional functions (startTime, endTime) to help with on-chain time management.
  • Some NFTs have a defined usage period and cannot be used outside of that period.
  • With traditional NFTs that do not include time information, if you want to mark a token as invalid or enable it at a specific time, you need to actively submit a transaction—a process both cumbersome and expensive.

How the mechanism is specified

  • Taken from the specification, the next constraint is: Some NFTs have a defined usage period and cannot be used outside of that period.
  • Locate MUST, NOT, REQUIRED in ERC 5007 and apply it to one transaction or call.
  • Then check the failure the class of rule always has: a node that did not upgrade, a reverted call, a replayed signature, or a peer that does not speak the message.

What this page does not treat as proven

  • A signature scheme is not a privacy system. It hides the signer only if the protocol says so.
  • Wallet support is not the same as consensus validity.
  • The source marks this final. That is a statement about the text, not a promise that every wallet or node has shipped it.

Why a venture studio still reads it

Use ERC 5007 when a pitch says 'Time NFT, ERC-721 Time Extension' without saying whether the rule is consensus, policy, or an interface. The number is the citation. The pitch is not.

This is Blockchain Lab's reading of a public design paper. It is not the paper, not a copy of it, and not an offer of tokens, equity, custody or a partnership. Later network behaviour can diverge from the text. Nothing here is investment, legal or technical advice.

Research status: Design paper. Last reviewed: 1 October 2026. This is a reading of a public paper, not investment, legal or security advice.