The 29th of February is a date that usually occurs every four years, and is called leap year day. This day is added to the calendar in leap years as a corrective measure, because the earth does not orbit around the sun in precisely 365 days.
In the British Isles, it is a tradition that women may propose marriage only on leap years. While it has been claimed that the tradition was initiated by Saint Patrick or Brigid of Kildare in 5th century Ireland, this is dubious, as the tradition has not been attested before the 19th century. Supposedly, a 1288 law by Queen Margaret of Scotland (then age five and living in Norway), required that fines be levied if a marriage proposal was refused by the man; compensation ranged from a kiss to £1 to a silk gown, in order to soften the blow.
In some places the tradition was tightened to restricting female proposals to the modern leap year day, 29 February, or to the medieval (bissextile) leap year day, 24 February.
In Denmark, the tradition is that women may propose on the bissextile leap year day, 24 February, and that refusal must be compensated with 12 pairs of gloves. In Finland, the tradition is that if a man refuses a woman's proposal on leap year day, he should buy her the fabrics for a skirt, while in Greece, marriage in a leap year is considered unlucky. One in five engaged couples in Greece will plan to avoid getting married in a leap year.