All funds required to be allotted under section
2852 or
2862 of this title shall be allotted within 45 days after the date of enactment of the Act appropriating the funds, except that, if such funds are appropriated in advance as authorized by section
2939
(g) of this title, such funds shall be allotted or allocated not later than the March 31 preceding the program year for which such funds are to be available for obligation.