Well done, thowan, you’ve made a lot of progress since the post where you said “I must insist that by tradition, leap day is still the 24th of February and not the 29th”.
It’s certainly not the tradition everywhere.
Well, RM Mentock, it is tradition in Denmark, whatever that’s worth. But thank you for your openmindedness.
And in Sweden, although the almanac publishers have for some reason chosen to call the 29th leap day. I don’t. 
I don’t doubt that the 24th was traditionally the leap day, but apparently even in Scotland people have given over that traditional value in favour of the rational value, even with respect to the women-proposing tradition. This article talks about the leap year tradition, and mentions only the 29th…
Most saints have feast days that are optional celebrations. Very few are always observed. It’s usually just ones like St. Joseph or one of the Apostles. Even St. Patrick’s Day is an “optional” feast.
Unless the parishioners feel some sort of connection with a particular saint, the priests won’t bother observing the feast day during the daily Mass. And all that usually consists of is the priest saying a specialized prayer or two during Mass.
I figure I’ll just add to the confusion. Again from the Oxford English Dictionary, for Leap Year
and Quotes:
So if you look at the definition of a Leap Day, they say it is the 29th, but if you look at Leap Year, it is the day that is leapt over (in agreement with thowan’s pushing back of holidays). At least when I think of leap, thowan’s explaination seems better. If not, why not just call it a long year or something more descriptive. Ah, well…
Interesting… I’m a bit late seeing as it’s March already, but just have to say that thowan is correct when talking about European tradition. Because in Finland, the leap day was indeed 24th, too. I have not only clear personal experience but also cites of this in Finnish and Swedish. Only recently we ceased to follow Caesar’s orders and in 2000 the leap day was moved to 29th. Thus 1996 was the last year when the leap day was traditional February 24th, like it always had been (an exception was year 1828, when it was Feb 25th for unknown reason). See examples of old calendars here (fin) or here (swe), leap day is called karkauspäivä / skottdagen. More calendars in main page.
My Simpson’s calendar makes no mention of “leap day” on either the 24th nor the 29th.
It does, however, mention that the 24th is International Pancake Day.
Hope this helps.