A strict observer of the Sabbath, there was to be nothing done on a Sunday, even during the year that the day of rest fell on the lone dry hours of a particularly wet harvest.
It was at 2am the next morning when McBride and his brothers were woken. The Sabbath was over, they were to cut corn in the moonlight.
After a childhood spent rising with the lark to carry out such duties, old habits evidently die hard. Turning 80 tomorrow, you still have to catch Willie John early to catch him at all. Even in these slower-paced days, plenty still needs done.
Sometimes it feels like I've lived four lives. The farm, banking, international rugby and then a retirement doing all sorts of things.
Living outside Ballyclare on around three acres with his wife Penny, there is grass to be cut and hedges to be trimmed, chickens to be fed and donkeys to be watered, vegetables to pick and a greenhouse to be tended to.
"And after all that," he says, "if there's nothing else to do, I'll find something. I still feel in great nick. That's the amazing thing, for all the physical punishment I put my body through playing over the years, the only thing that gives me any trouble is a knee I had to replace a few years ago. I'd no other real injuries and was able to finish every game I started."
He neglects, of course, to mention that on one occasion he did so with two broken bones in his leg.
Until the world changed quite so dramatically a few months ago, these tasks around the garden had to be fitted around a stacked social calendar too, his status as an icon of Ulster, Ireland and Lions rugby naturally keeping him in high demand.
Chief among the many events he'd have been attending in more ordinary times would have been his own birthday celebrations, the pre-lockdown plan a black-tie dinner in The Culloden. Eleven former Lions captains had readily cleared the date in their diary in order to mark the beginning of the great man's ninth decade and to benefit Wooden Spoon, the charity for which McBride has been Ulster president since their inception 25 years ago.
"Well I was surprised anyone would be interested in an old 80-year-old anyway but there you go," he laughs of the postponed event that had long since sold-out and filled a lengthy wait-list. "At 80 years of age, and with everything going on in the world, it's not something I'd feel is worth getting too excited about.
"These things happen and just you have to go with them, that's life. The only thing I'd feel bad about is the charity because they do so much good work but hopefully we can do it all just as well at a later date."
Tomorrow's milestone will be spent with close family. He wouldn't want it any other way.
The most globally evocative name in the history of Ulster Rugby, the most capped British and Irish Lion of all time, captain of the historic 1974 'Invincibles', a CBE, a Freeman of the Borough, Heineken Rugby Personality of the Century and even a one-time Pipe Smoker of the Year, the title he takes the most joy from at present is that of great-grandfather.
Flanked by his wife Penny, his children, his children's children and the kids of their own, he'll reflect on how lucky he feels, even if there is always a tinge of melancholy to such gatherings.
Not all the men of the McBride clan have been so blessed. His father died when only in his 50s, his brother Tom, three years younger and who himself would have been celebrating his own birthday today, drowned in 1963.
Throughout McBride's life, neither man has been far from his thoughts, especially at times such as these.
"Even still, at 80-years-old, I often wonder what life would have been like if my Dad had been around," he says.
"We lost him when I was four. I never had that father figure around.
"I was probably too young to really understand what had happened. He dropped dead in a potato field in October, Halloween night. In those days there was no such thing as a post-mortem, it was just sudden death, we never really knew. Whether it was a blood clot or a heart attack, we never knew, it was never really discussed. I don't have many memories, I remember him being carried in from the field. I remember crying that he was gone. I remember sitting on his knee and him singing, he was a great singer.
"It was very sad and you kept wishing that one day he'd just walk through the door.
"That's a long time ago, 1944, during the war, but even now, every Halloween, the first thing that hits me is my father's death. Even at 80 years of age."
With his father's untimely passing, sport was the furthest thing from the mind of the young McBride. With all there was to be done at home, there was simply no time. For all that he went on to achieve, perhaps the most incredible feat of his career is that he didn't play an organised game until he was 17.
Winning the first of his 63 caps Ireland caps against England in Twickenham as a 21-year-old, he'd play in a Test before he'd ever watched one. The journey from not knowing the laws on Ballymena Academy thirds to a Lions tour in South Africa took him all of four years.
McBride with his famous Lions mascot during the South African Tour of 1974.
"Well it would never happen today," he says, with a degree of understatement. "My mother was amazing, she was a tremendous woman but she really had no idea what rugby was about or what it was that I was trying to do with myself.
"They were tough days on the farm back then, no tractors for sure. When I was brought up it was without electricity or running water. We all had our responsibilities to take care of so there wouldn't have been many hours to spare."
Somehow he found the time, as well as money for the boots. One wonders how different his life would have been if he hadn't. It's a theme he returns to again and again, those slices of fortune, whether it be his late-blooming or having found employers like Northern Bank who would allow him to miss such significant time to play on the tours that would come to define his place in rugby history.
When he says he couldn't have done any of the things he did on the field without the support of his wife of 54 years, he laughs recalling how their blind date came only to pass thanks to the favourable flip of a coin.
"We're still here so there must have been something," he says. "Eighty years is obviously a reasonable amount of time to look back on it all and when I do from time to time, I just feel very fortunate.
"Sometimes it feels like I've lived four lives. The farm, banking, international rugby and then a retirement doing all sorts of things.
"There have been ups and downs and bumps in the road but by and large it's been great. I've done a lot of things, had a few exciting times and I feel very fortunate.
"It's nice for me to think back on it all and realise I've a lot of friends still today that I've come to know through rugby. I've been in touch with a lot of them recently since this stupid virus just to see how they are, to make sure they're well and to see how they're getting along.
"Looking back on it, yes there were Triple Crowns we could have won or some championships but if we'd been good enough, we would have. There are no regrets in that sense, there are just great memories and great people.
"When I think about it, you know, it was all about people."