What steps will reproduce the problem? 1. Code should allow to submit only year, but not month or day in the openid.sreg.dob 2. Currently it is not allowed due to DateTime? type used in the class and therefore it is impossible to pass date like 1980-00-00, which is valid according the spec (see http://openid.net/specs/openid-simple-registration- extension-1_0.html, section 4. Response format, openid.sreg.dob) 3. Also, operation ToString() may generate values that do not match the specified format if running in non-english environment

What is the expected output? What do you see instead? The expected format of the openid.sreg.dob is string, however validated (e.g. using regex and some custom logic)

Please use labels and text to provide additional information.

Thanks for filing this report. You're absolutely right about this issue, and it's the result of a design decision deliberately made, based on the observation that virtually no one seemed to use this particular partial-date feature of sreg. Since you seem to have a need for it, we can add a new string property that captures the original value after validating it as you've requested.

Scheduling this for v2.6.

Fixed by adding a new ClaimsResponse.BirthDateRaw property that is a string and allows for incomplete dates.

Fixed in 1c2da28ecb93c839f4bce464085e9f6b6db27ca6.