3 U.S.C.
United States Code, 2007 Edition
Title 3 - THE PRESIDENT
CHAPTER 1 - PRESIDENTIAL ELECTIONS AND VACANCIES
Sec. 2 - Failure to make choice on prescribed day
From the U.S. Government Publishing Office, www.gpo.gov

§2. Failure to make choice on prescribed day

Whenever any State has held an election for the purpose of choosing electors, and has failed to make a choice on the day prescribed by law, the electors may be appointed on a subsequent day in such a manner as the legislature of such State may direct.

(June 25, 1948, ch. 644, 62 Stat. 672.)