1. The board of elections shall cause all military ballots received by it before the close of the polls on election day and all ballots contained in envelopes showing a cancellation mark of the United States postal service or a foreign country's postal service, or showing a dated endorsement of receipt by another agency of the United States government or are signed and dated by the voter and one witness thereto, with a date which is ascertained to be not later than the day before election and received by such board of elections not later than seven days following the day of a primary election and not later than thirteen days following the day of a general or special election to be cast and counted.
2. The board of elections shall thereafter process such ballots in the manner provided in this chapter for processing absentee ballots.