It has happened to every person who ever wanted an Egg McMuffin but overslept. You get to the McDonald's (NYSE:MCD) counter, place your order, and the clerk tells you that it is too late to order breakfast.

This problem has plagued the Golden Arches and other fast food chains since breakfast joined the menu at McDonald's in the early 1970s. People want their eggs, pancakes, hash browns, and various breakfast sandwiches, but at some point -- largely due to equipment limitations -- the eateries had to switch to their lunch menus.

Whether it was 10:30, 11:00, or even 11:30, a deadline had to be set when morning fare would transition into burgers and French fries. The switch generally left some customers frustrated, but societal norms made it clear that breakfast foods were mostly for mornings.

However, those norms are changing, and new research shows that a majority of Americans want breakfast served all day, especially Millenials.

What the survey says

At some locations, part of the McDonald's breakfast menu is served starting at midnight. Source: McDonald's

Seven out of 10 consumers say they want restaurants to serve breakfast throughout the day, according to the 2015 Restaurant Industry Forecast from the National Restaurant Association. According to the study, Millennials -- the generation which reach adulthood around the year 2000 -- are more interested in breakfast for dinner than any other age group before them.

"Breakfast hasn't traditionally been the most common dining-out daypart, but with the increasingly busy lifestyles we lead today, consumer interest is definitely stemming from the blurring of normal meal periods," says Annika Stensson, director of research communications for the association. "Who doesn't like some good pancakes, no matter what time of day it is?"

McDonald's problem
While moving to offer breakfast all day might help McDonald's turn around its lagging sales in the United States, operational concerns have stopped it from happening. The restaurants lack the space to prepare the breakfast menu alongside the lunch menu.

"We know, as an example, that breakfast on the weekend cut off at 10:30 doesn't go very well," Jeff Stratton, the former head of McDonald's USA told the Associated Press a little over a year ago. He acknowledged that the company was looking at remedies for the problem, but, in the year since that interview took place, nothing has happened.

J.M. Owens, a longtime franchisee explained the problem in depth in a 2013 interview with Burger Business:

First there are some capacity issues. We only have so much toaster space and so much grill space. Unlike a lot of breakfast QSRs, we still cook our product on a grill. Many of the pretenders are doing a ton of prep in microwaves. For instance, go into a Dunkin' Donuts or a Starbucks, who are chasing breakfast, and you don't find a grill or oven or fryer. We prefer to be a restaurant rather than processing everything through a microwave.

Those are the issues long cited as the reason the chain can't make breakfast an all-day affair, but the failure to address them may well be part of McDonald's continued sales slump.

Competitors moving in
Owens may have dissed efforts by Dunkin' and Starbucks to steal a piece of the breakfast business, but those chains are part of a wave of quick serve restaurants which are moving to offering traditional morning fare all day long. One such competitor -- another chain built on burgers and fries -- Sonic has found success with day-long breakfast.

"At breakfast, we focus on unique menu items that we can offer quickly and consistently," Sonic CMO Todd Smith told QSR Magazine. "Those same items -- like our Breakfast Burritos and Breakfast Toaster Sandwiches -- also happen to be great options for other dayparts."

He explained that offering breakfast all day is a logical part of the chain's philosophy of "giving the customer what they want, when they want it."

McDonald's seems unlikely to change
While there is overwhelming customer support for day-long breakfast, and the morning menu has the highest margin of any of its offerings, the company seems unlikely to make it a reality. 

"It comes down to the sheer size of kitchen grills," the company wrote on its website in response to customer questions about all-day breakfast. "They simply don't have the room for all of our menu options at one time -- especially considering we use our grill to prepare many items on our breakfast menu."

McDonald's seems to want to offer breakfast all day, but it can't without adding equipment or changing how it operates. Those changes seem unlikely to come any time soon -- if at all -- even if seven out of 10 Americans would be "lovin' it."