If we want relational system in conjunction with time we use sixth normal form. At this moment SQL Server does not supports it directly.

Yes, I’m familiar with the concept of sixth normal form (6NF) in database management systems (DBMS). It’s an advanced level of normalization in which every non-trivial join dependency in the table is a logical consequence of the candidate keys. This form is rarely used in practical database design due to its complexity and limited applicability. It’s more of a theoretical concept used to demonstrate the principles of normalization beyond the third normal form (3NF).