Here's some additional interesting information about February 29th.
St. Bridget's Complaint
It is believed this tradition was started in 5th century Ireland when St. Bridget complained to St. Patrick about women having to wait for so long for a man to propose. According to legend, St. Patrick said the yearning females could propose on this one day in February during the leap year.
February 29th in English Law
According to English law, February 29th was ignored and had no legal status.
Folks assumed that traditions would also have no status on that day. It was also reasoned that since the leap year day existed to fix a problem in the calendar, it could also be used to fix an old and unjust custom that only let men propose marriage.
The first documentation of this practice dates back to 1288, when Scotland passed a law that allowed women to propose marriage to the man of their choice in that year. They also made it law that any man who declined a proposal in a leap year must pay a fine. The fine could range from a kiss to payment for a silk dress or a pair of gloves.
Sadie Hawkins Day
In the United States, some people have referred to this date as Sadie Hawkins Day with women being given the right to run after unmarried men to propose.
Sadie Hawkins was a female character in the Al Capp cartoon strip Li'l Abner. Many communities prefer to celebrate Sadie Hawkins Day in November which is when Al Capp first mentioned Sadie Hawkins Day.
There is a Greek superstition that claims couples have bad luck if they marry during a leap year. Apparently one in five engaged couples in Greece will avoid planning their wedding during a leap year.