La. R.S. 38:1779

The polls shall be open on the date appointed at 7 o'clock A.M., and remain open until and not later than 6 o'clock P.M. No election shall be vitiated by the failure to open the polls at the time prescribed or by closing them before the time prescribed, unless on a contest, it be established that voters were thereby deprived of votes sufficiently in number and amount to have changed the result of the election.