Credentials
actualDuration
LearnCoin extension field recording how long a specific recipient actually took to earn a credential — distinct from OB 3.0 achievement.duration (the typical duration).
Open Badges 3.0 defines achievement.duration as the typical time an achievement takes — a class-level property of the Achievement. But issuers often want to record how long this specific recipient actually took, which is an instance-level fact belonging to the credential, not the achievement.
LearnCoin's credentialSubject.actualDuration extension fills that gap. It's an ISO 8601 duration string living in the LearnCoin-specific JSON-LD context (schema.learncoin.me/v1/context.json — publication pending). Tenants pass actualDuration through the POST /v1/batches API; once the extension context ships, it becomes cryptographically committed inside the signed credential.
The distinction matters for verification semantics. A recruiter looking at two credentials for the same achievement might see one recipient completed it in the typical six weeks and another in three months. Both credentials are valid; the actualDuration field gives the verifier more signal without changing the underlying achievement.
Related terms