PostgreSQL seems to convert those two formats into the same format we validate here.

`DateValidator` uses the `yyyy-mm-dd` format for validation, even though `mm/dd/yy` or `dd/mm/yyyy` are "potentially valid".

For the sake of consistency, I feel we should enforce this format as-is.  If a developer needs to support non-compliant formats, they can easily extend this validator and adjust the `PATTERN` as needed.