Before you pass out, please answer this important question.
It’s St. Paddy’s day. “Paddy” is the diminutive for the Irish name Pádraig, which was his name. No self-respecting Irishman would let anyone call him “Patty.”
Although my phone wants to keep calling it “St. Party’s day,” which works just as well, I suppose. 
It’s Patrick, not Patricia.
I voted Paddy, but my spouse is horrified at me. So…half each way?
Quite, Patty is a girl’s name.
For non-Gaelic speakers (like myself) I guess I feel that if it was popularly known as “St. Padraig’s Day” it would be okey dokey to say “Paddy” but for us English speaking monoglots “Patty” will have to do.
I’ve never heard “St. Patty’s” seeing at “Patty” is not a variation of “Patrick” but “Paddy” is.
Never heard Patty.
Except that Patty is still a girl’s name, and not a diminutive of Patrick in the English language. Paddy is universally used in the english language as the short from of Patrick (along with Pat).
I just assumed that after a few whiskeys all Ts start sounding like Ds.
Its neither, in Ireland we say Patrick.
I hate cutesy nicknames. If you can’t call it St. Patrick’s Day, don’t talk to me about it.
It’s the dark secret of St Patrick: he wasn’t Irish. He was an English missionary who went to Ireland.
This is what I was going to post.
While I agree with the use of “St. Paddy’s Day” as the shortening (and also agree that I usually just call it St. Patrick’s Day), Little Nemo is correct to point out that Patrick wasn’t Irish. He was born in Roman Britain, and the few extant works that are believed to have been written by the man himself are all in Latin.
Writing in Latin as he did, the only name he ever actually calls himself is Patricius. It’s not certain exactly where he was born, so we can’t really say what the form of his name might have been in his native vernacular, if indeed he spoke a language other than Latin in his daily life.
I didn’t vote. I’ve heard from enough sources that “Paddy” is the correct spelling that I’m not going to stubbornly insist that it’s not. However, Patrick get shortened to Pat, not Pad. And by that logic, Pat should turn into Patty, not Paddy. And all this stuff about Paddy being short for Padraig seems completely beside the point to me, since it’s not called St. Padraig’s Day.
While I will not claim that Patty is the *correct *spelling, I will say that it’s the spelling I prefer, whether or not it’s officially correct.
Is St. Pat’s OK? That’s what I say/type.
I’ll concede that, but I’ll bet he was known as Father Paddy to the locals.
Well technically his name was Patricius. He was Romano-British and wrote his name in Latin. Padraig is the Irish spelling of his name, as Patrick is the English version.
Edit: Or what MrAtoz said.
I vote Patty’s, but AIUI many Irish vehemently loathe anything other than the proper “Patrick’s.”