Daine v. Commissioner
In Daine v. Commissioner, 168 F.2d 449 (2d Cir. 1948), the Court disallowed the deduction from the husband's 1943 income of support payments made under a 1940 separation agreement embodied nunc pro tunc in a 1944 separation decree.
The court refused deduction under the nunc pro tunc decree on the ground that the New York court could not establish the fact of legal separation for federal tax purposes as of a date when there was no legal separation in reality. (168 F.2d at 451)