The trend started in the 1970s

ND's opener was October 4 as late as 1947, and September 30 as late as 1961. The first time ND played two games in September was 1965 -- at Cal on the 18th and at Purdue on the 25th.

The two factors that led to earlier season openers were an increase of the maximum schedule from 10 games to 11 in 1970, and the proliferation of TV games. Through 1973, ND's earliest-ever opener had been September 18, in both 1965 and 1971. But the 1974 game at Georgia Tech was moved from November 9 to September 9, a Monday night, for ABC-TV. The following year, the game versus BC in Foxbor was actually moved back from September 13 to September 15, also for a Monday night telecast. The Pitt games in 1976 and 1977 were moved from October to September 11 and 10 for TV. The 1978 opener, versus Missouri on September 9, was the earliest at the time which was not related to the TV schedule.

In 1983, the first Kickoff Classic was played, and it was the first time a regulation college game was scheduled for August. In 1984, the NCAA's TV contracts were voided by the Supreme Court on antitrust grounds, which induced more and more teams to schedule earlier and earlier openers to accommodate TV. There were a few teams that opened 1985 on August 31. Such early openers became even more common through the 1990s and nearly universal by the 2000s.