1984.
WikipediaBig Boy Restaurant Group, LLC is an American restaurant chain headquartered in Warren, Michigan, in Metro Detroit. Frisch's Big Boy Restaurants is a restaurant chain with its headquarters in Cincinnati, Ohio. The Big Boy name, design aesthetic, and menu were previously licensed to a number of regional franchisees.
https://en.wikipedia.org/wiki/Big_Boy_Restaurants[https://en.m.wikipedia.org/wiki/Big_Boy_Restaurants]
"Shoney's/Parkette (Tennessee, Alabama, Arkansas, Mississippi, Louisiana, Georgia, Virginia, South Carolina, North Carolina, West Virginia, Maryland, Missouri, New York, Philadelphia, PA, 1952–1984, founded by Alex Schoenbaum)."
" In April 1984 Shoney's Inc.—by then the largest Big Boy franchisee with 392 units—paid $13 million to break its contract with Big Boy, allowing expansion into Frisch's and other franchisees' Big Boy territories".
So I'm referring to Shoneys Big Boy specifically. I grew up in Virginia and I remember my mother asking us kids "would you like to go to Shoneys?" while out shopping on a Saturday night and we would squeal with delight.