IIUC, you have a calc field that references another date field.
The pre-build conditions only consider to the field in question itself. If you want to make the formatting dependent on another field, use
IsEmpty ( YourTable::yourDateField )
If I understood incorrectly and you're talking about a single field, try
IsEmpty ( self )
Make it a date field that stores a calculation, not a calculation-type field that stores the date
Make it a date field that stores a calculation …
And here I was thinking a date field is only capable of storing a date …
The field that I'm trying to format is the actual calculated field, not the field(s) used by the calculation.
To the eye the field is empty.
However, the test IsEmpty(self) does not trigger the conditional formatting. I therefore assume that while it may look "empty" it actually has a non-empty value hidden away.
I tried converting the calculation to a number (rather than a date) to use a numeric condition, but I was unable to format the field on the layout as a date.
I therefore assume that while it may look "empty" it actually has a non-empty value hidden away.
In that case, study your own calculation closely and see what the default content will be. Post it here if you want others to take a look.