Standardize on date format for date of incorporation or registration

[clintwilson]

@timfromdigicert identified a useful improvement to the EV Guidelines:

The following text is current in the EV Guidelines, section 9.2.5:
“If the Jurisdiction of Incorporation or Registration does not provide a Registration Number, then the date of Incorporation or Registration SHALL be entered into this field in any one of the common date formats.”
Is there any reason why we shouldn’t standardize on an ISO 8601 date format like YYYY-MM-DD?
Obviously, this would require time to implement for CAs that might be using alternative formats, but I’m not sure what the value is of allowing flexibility in this particular field.

@sleevi agreed this would useful to align on. I echo that agreement as well; we should identify a well-specified date format compatible with the goals here (e.g. it's rare for incorporation dates to be more granular that Day+Month+Year).

Using ISO 8601's Complete Date format as Tim described seems like a good starting point (YYYY-MM-DD (e.g. 2020-01-23).

[barrini]

still ongoing and perfect for an easy ballot