When will the great invasion of the northern armies occur relative to the Antichrist's treaty?

Les explains that the great invasion and destruction of the northern armies will occur shortly after the Antichrist signs the treaty, within the first 12 months. People object that this cannot fit inside the seven years because there would not be enough time to finish, but he argues from the chronology of Scripture that the Bible ascribes a whole year to anything covering part of a year. For example, if a king ruled 10 years and one month, the Bible would say he ruled 11 years. Applying that rule, if the invasion took place in the 10th month after the treaty, with two months left in that first 12 months, the Bible could refer to it as a full year. Thus, shortly after the treaty is signed, within the first 12 months, the great invasion and destruction of the northern armies occurs, and they still have seven years in Biblical chronology to burn the weapons. Les also comments that the burning may be out of date, but you never know.