The charts above reflect the results of the recent Politico / Morning Consult Poll -- done between September 25th and 27th of a national sample of 1,986 registered voters, with a 2 point margin of error.
It shows that a plurality of voters (47%) don't expect to know the winner of the presidential election on election night.
A majority (65%) does expect to know within a week though (20% on election night, 19% on the next day, and 26% within a week).