Leap Year Trivia

A leap year is a year in which one extra day has been in-
serted, or intercalated, at the end of February. A leap
year consists of 366 days, whereas other years, called
common years, have 365 days.
***
The vernal equinox is the time when the sun is directly
above the Earth's equator, moving from the southern to
the northern hemisphere. The mean time between two suc-
cessive vernal equinoxes is called a tropical year–also
known as a solar year–and is about 365.24 days long.
Using a calendar with 365 days every year would result
in a loss of 0.24 days, or almost six hours per year.
***
By adding a leap year approximately every fourth year,
the difference between the calendar and the seasons can
be reduced significantly, and the calendar will align
with the seasons much more accurately.
TRADITIONS AND SUPERSTITIONS
A tradition was introduced many centuries ago to allow women
to propose to men during a leap year. This privilege of pro-
posing was restricted to leap day in some areas.
***
Leap day was sometimes known as 'Bachelors' Day'. A man was
expected to pay a penalty, such as a gown or money, if he
refused a marriage offer from a woman. The tradition's
origin stemmed from an old Irish tale referring to St.
Bridget striking a deal with St Patrick to allow women to
propose to men every four years. This old custom was pro-
bably made to balance the traditional roles of men and
women in a similar way to how the leap day balances the
calendar.
***
It was also considered to be unlucky for someone to be born
on a leap day in Scotland and for couples to marry on a leap
year, including on a leap day, in Greece.