29 February ... And I didn't get a silk gown...!

Due to the vagaries of our calendar, every year whose number is cleanly divisible by four is a leap year, and so contains an extra day tacked onto its February. Because leap years are seen as unusual events that disturb the otherwise orderly progression of days/months/years, certain beliefs have been attached to them. According to folk tradition, 29 February is the only time when a woman could propose marriage to a man, termed "The Ladies' Privilege."
In1288, Queen Margaret of Scotland decreed that a woman could – on 29 February – propose to a man; which, so entreated, the man must either accept the proposal or pay the refused woman a substantial forfeit for turning her down, such as a silk gown or ℓ100.
The origins of "The Ladies' Privilege" are not definitively known, but one posited beginning set in Ireland had St. Bridget complaining to St. Patrick about women not being able to ask the men they fancied to marry them. According to the folktale, he offered the opportunity at a seven-year interval, and she bargained him down to four. (If this tale is true, it's no wonder St. Patrick took to putting the run on snakes, because he sure wasn't doing well against women.)
Though everyone loves a good folktale, the beginning of this custom more likely has to do with February 29 being perceived as a day that does not properly belong on the calendar and thus as a period when the ordinary rules of conduct do not apply. Other superstitions play upon the underlying theme of "betwixt and between" times being occasions especially fraught with peril or periods when the unusual was not only allowed to occur, but was encouraged to do so.
There is a bit more to leap year lore besides girls suddenly popping up to hold out velvet-covered ring boxes to their beaux. Superstition decrees leap years are notably excellent for beginning important undertakings or business ventures. The choice of itself is deemed particularly astute in that even greater luck will attach to all that is begun on that day.
... Queen Margaret.... and "The Ladies' Privellege"....
29 February ... And I didn't get a silk gown...!