A form heading that is the Duration operation type can function without any prerequisite. However, it may be useful to have two Date hour headings in the same form.
A Duration operation dimension heading that is non persistent requires one or two headings from the same dimension and their type must be:
Date hour,
or Events values (persistent or not).
A Formula operation heading that is non persistent requires one or two headings from the same dimension and their type must be:
Control column (persistent or not),
Operation (persistent or not),
or Events values (persistent or not).
A Duration operation dimension heading that is persistent requires one or two headings from the same dimension and their type must be:
Date time,
or Persistent Events Values.
