I using DATE(Cell1,Cell2,"d"), the result is always 0.

I used the evalute forumula and here is what it says :

Datedif(39236,39266, "d"). How can the result be 0. Cell1 and Cell2 are
calculated fields with a format of custom (mmm dd yyyyy). I have tried
changing the format to date but still the same effect.

The calculations in the cell1 and cell2 are Date(Year(cell5),
Month(cell5)+1, Day(cell6).

Help - this is driving me crazy.