Inconsistent type for `activityStartDate` and `activityEndDate`

[daniel-mader]

The activityStartDate and activityEndDate use the DateTime type.
According to the spec, the DateTime (primitive type) uses the syntax YYYY-MM-DDThh:mm:ss.
However, in the examples "activityStartDate": "2010-01-01T00:00:00Z" has the offset included.

Which one should be followed? Is the offset optional?

[ottonomy]

I would expect that all datetimes in the spec should have the time zone / offset. We'll discuss this at the working group tomorrow.

But I think this might have been defined as a "Date" rather than a particular moment in time, similar to how many offline documents will print a date after which it expires.

The JSON-LD context says date:

"activityStartDate": {
          "@id": "https://purl.imsglobal.org/spec/vc/ob/vocab.html#activityStartDate",
          "@type": "https://www.w3.org/2001/XMLSchema#date"
        }

This would expect just a date, e.g. 2025-12-31 no timestamp at all.

But the JSON-schema has:

"activityStartDate": {
      "description": "The datetime the activity started.",
      "$comment": "Origin: DateTime (PrimitiveType); An [[ISO8601]] time using the syntax YYYY-MM-DDThh:mm:ss.",
      "type": "string",
      "format": "date-time"
    }

specifying YYYY-MM-DDThh:mm:ss

My read is that the schema needs an errata change (and bugfix in schema generation code) to allow us to properly specify the Date type as intended.