Add birthDate field to align on the standard date format

[cfraser]

• add birthDate field as described in issue Combine individual Birthday fields to a single field of format: 'date-time' #469

[fmeschbe]

Let's see whether we find a good regex instead of format:date which does not cope with incomplete dates.

[fmeschbe]

As per the discussion, we don't want to have this to be date since the date might be incomplete. We discussed using a regular expression to match a date, so that we can be sure it is properly formatted.

Something along these lines:

"pattern": "([0-9X]{4}|XXXX)-([0-9]{2}|XX)-([0-9]{2}|XX)"

[HyveMynd]

I believe that pattern is an acceptable ISO format, is it not? If so, the date format is enough.

[fmeschbe]

It is @HyveMynd. The problem is how to deal with incomplete dates. For example, when we don't know the year.

[kstreeter]

Hey @cfraser (and @fmeschbe). My suggestion is that we have three distinct fields which capture the specific cases we have for birthday. I feel like this will make the interpretation of each field simpler:

• xdm:birthDate - the full date, using the "date" format
• xdm:birthDayAndMonth- the regex "XXXX-MM-DD" as @fmeschbe suggested
• xdm:birthYear - the birth year, which can be used to compute age

I am a bit concerned about allowing partial dates in the same field as you would expect a full date. This puts a lot of burden on readers to handle partials, and won't allow standard tooling to expose full dates as standard data types (like the Java Date class).

[fmeschbe]

@kstreeter The main concern is indeed how to handle partial dates. The standard Java classes do not seem to be ready to support this case properly. So an unknown day could default to first, while an unknown month would become January, and an unknown year .... (I don't know).

But that is not of a concern for XDM as a transfer format, is it ?

[cfraser]

Closing in lieu of #498.