Thursday is the day of the week between Wednesday and Friday. According to the ISO 8601 international standard, it is the fourth day of the week. In countries which adopt the "Sunday-first" convention
1. Compute SHA-256 of OTSCanonicalRecord value → must equal OTSHash 2. Open OTSProofURL → extract Bitcoin block number → must equal OTSBitcoinBlock 3. GET OTSBitcoinBlockVerifyURL → returns the Bitcoin block hash at height OTSBitcoinBlock; GET https://blockstream.info/api/block/{that hash} → its timestamp must match OTSTimestamp 4. Read CopyrightID inside OTSCanonicalRecord → must equal the CopyrightID above 5. GET OTSVerificationAPI → pre-computed 6-check result from server 6. If all match: this entity was registered on CopyrightChains at OTSTimestamp, independently verifiable on Bitcoin Note: an OTS proof may carry multiple Bitcoin attestations; OTSBitcoinBlock is the earliest confirmed one — a later attestation inside the proof corroborates it and is not a mismatch
Dual-chain trust anchor. Chain 1 (CopyrightChains): CopyrightID 0xa0973cebb2f75f43ed898adfca989155e307a42400babf6b9f3be3db6a0ed8a1. Chain 2 (Bitcoin): anchored in block 953997 (2026-06-16T20:07:57Z). Bridge: the canonical record inside this Bitcoin proof contains the same CopyrightID. Verify: download https://artists.proofprofile.net/proofs/artist/2f80d916-3d7c-40d8-b16b-62228c691ca1.json and https://artists.proofprofile.net/proofs/artist/2f80d916-3d7c-40d8-b16b-62228c691ca1.ots, run `ots verify -f record.json proof.ots` (https://opentimestamps.org).