In the band "Lahaqat haTaltin" (Shamrock Ceoili Band) where I started as guitarist in 1998, just after St.Patrick's day celebration, in Haifa, the following version was accepted:

On the eighth day of March it was, some people say,
That St.Patrick at midnight, he first saw the day;
While others declare 'twas the ninth he was born,
And 'twas all a mistake between midnight and morn.
And some blamed the baby and some blamed the clock;
Till with all their cross questions, sure no one could know –
If the child was too fast or the clock was too slow.

Now the first faction fight in auld Ireland, they say,
Was all on account of St.Patrick's birthday;
Some fought for the eighth, for the ninth more would die,
And who wouldn't see right, sure they blacken'd his eye!
At last both the factions so positive grew,
That each kept a birthday, so Pat then had two;
Till Father O'Brien, who showed them their sins,
Said, "No one could have two birthdays but a twins".

Says he, "Boys, don't be fighting for eight or for nine,
Don't be always dividing, sometimes combine;
Combine eight with nine – seventeen is the mark,
So let that be his birthday." "Amen," says the clerk.
"If he wasn't a twins, sure our history will show,
That at leas he's worth any two saints that I know!"
Then they all got blind drunk, which completed their bliss,
And we keep up the practice from that day to this.

The author of this poem is unknown to me, but I can ask Michael, our leader.