La. R.S. 38:1858

The polls shall open, on the day appointed, at seven o'clock A.M. and shall remain open until and not later than six o'clock P.M. No election shall be vitiated by a failure to open the polls at the time prescribed, or by closing before the time prescribed, unless, on a contest, it be established that voters were thereby deprived of votes sufficient in number and amount to have changed the result of the election.