In theory you can use any pattern of these codes to represent various date time formats.
In practice only a number of patterns are detected by the Guess Column Properties and support by the Set Column Properties and Validation features:
Data Curator Issue
The technical aspects of this known problem are discussed in Data Curator issue #483 on GitHub.
Planned Resolution Date
Data Curator uses the Frictionless Data tableschema-js software library to guess column properties and perform data validation. If this library is improved, then this issue may be resolved.