SINRA White Paper

5-4. NFT validity and expiration date

Regenerative NFTs have a predetermined validity period. The reason for setting this validity period is that while Regenerative NFTs are held by an unspecified number of individuals and entities both domestically and internationally, there's a risk that if the holder forgets about their titles, the environmental value represented by the NFT may not be offset and could end up lost.
To address the aforementioned risks, Regenerative NFTs have a validity period set based on the following criteria. This period is defined in terms of years and varies depending on the project and the duration of the project.
The validity period is applied when the project associated with the Regenerative NFT reaches the approved status (credit attached). Additionally, the start date of the validity period is reset to the date on which the Regenerative NFT is transferred.
In other words, the start date of the validity period for the Regenerative NFT is determined by one of the following moments:
・The time when the Regenerative NFT with the project approved status (environmental value created) is MINTed or transferred.
・If the NFT was MINTed during the project's project not applied, project applied, or project certified(credit not attached) statuses and subsequently reaches the approved status (credit attached).
It should be noted that the validity period does not apply to Regenerative NFTs that are in a retired or revoked state.
The time when the validity period has elapsed from the validity period start date is referred to as the "expiration date", and the NFT that has exceeded this expiration date will be in an "expired" state (refer to 4-2).
The expiration date is calculated as follows:
"Starting at 0:00 on the day following the validity period start date, and 0:00 after the validity period has elapsed is considered the expiration date."
Here, the time zone for each date and time is based on UTC.
For example, if the validity period start date is 7/15/2023 7:47 JST and the validity period is 8 years:
The validity period start date is 7/14/2023 22:47 UTC. Therefore, the next day, 7/15/2023, becomes the base date, and the expiration date is 7/15/2031 0:00 UTC (which corresponds to 7/15/2031 9:00 JST).