As a football league match was played on a Sunday in Northern Ireland for the first time, BBC Ireland correspondent Mark Simpson went along to hear the views on both sides.
Protesters in their Sunday best suits campaign outside the Oval
There was no clear winner as two of Northern Ireland's great passions - football and religion - clashed on the streets of east Belfast.
On the one side, there were around 50 protesters in their Sunday-best suits, campaigning to keep the Sabbath holy.
On the other side, were hundreds of fans in shiny football shirts, wanting to watch their favourite team.
Unlike many previous street protests in Belfast, this one was peaceful. Indeed, the only time voices were raised was when the demonstrators sang hymns.
And unlike most disputes in Northern Ireland, this one was not between Catholics and Protestants. This one was Protestant versus Protestant.
Sabbatarianism has always been a big issue in Northern Ireland. Although Belfast has followed the rest of the UK with a relaxation of the laws on Sunday trading, football has stayed fixed to Saturdays.
The match which broke the mould was held at Glentoran's stadium - The Oval - in the heart of east Belfast. The club's supporters are mainly Protestants.
When they arrived outside the turnstiles, they were greeted by a group of around 50 members of the fundamentalist Free Presbyterian Church, which was until recently led by the Reverend Ian Paisley.
"You hypocrites," shouted one fan as he walked past the Protestant protestors.
Another said: "If Sunday is the day of rest, surely they shouldn't be here protesting. They should be at home resting."
The demonstrators included men, women and teenagers, plus a number of clergymen who handed out religious leaflets to the passing fans.
A large sign was held up, with an Old Testament verse from Exodus - "Remember the Sabbath Day, to keep it holy."
Halliday (left) opposes Sunday games
The Rev David McIlveen insisted that staging top-flight Irish football on a Sunday in Northern Ireland was a step backwards, not forwards.
He said: "Fundamentally, it is a desecration of God's day. We do not believe that such activities should take place on the Sabbath day.
"We also recognise that it is going to be now a great temptation for young children to go away from afternoon Sunday schools, which have been the heart and soul of this community for many years. Therefore we feel that it is a detrimental step."
As for the fans, they voted with their feet - by turning up in their usual numbers. Indeed, some home fans suggested the attendance was slightly larger than normal.
So will this now start a trend, and a move from Saturday to Sunday football in Northern Ireland?
It is too soon to judge. The real test will come when a Sunday match clashes with a major game on Sky television. For example, in two weeks' time when Manchester United play Chelsea at 1400 BST.
The truth is that Irish League clubs are likely to tread carefully before taking a major step towards Sunday football. Like most things in sport nowadays, it is likely to be driven by money, and whether the crowds are bigger.
For the football fans who turned up at The Oval for the history-making game, it was not exactly a feast of football, as Glentoran scraped a one-nil win over Bangor.
As for the players, at least one of them is uncomfortable about the prospect of Sunday football catching on.
Glentoran striker Michael Halliday is a committed Christian. The 1500 BST kick-off meant he could still go to church in the morning, but he is not in favour of all football being played on a Sunday in the future.
He went home happy, though, as his team won. The home fans went home smiling too.
At the same time, the protesters left satisfied that they had made their point, and highlighted their biblical beliefs.
All in all, a score draw.