A leap year (also called a bissextile year) is a year that contains (=zawiera) one additional (=dodatkowy) day. Do you know why we do so? The reason for adding one day is to keep the calendar year synchronized (=zsynchronizowany) with the astronomical and seasonal year. In the Gregorian calendar (=kalendarz gregoriański) it is February that has 29 instead of (=zamiast) 28 days. What's interesting it is not the 29th that is the extra day - the additional day is the day inserted between the 23rd and the 24th. In the Hebrew Calendar (=kalendarz hebrajski) a leap year contains 13 months (an extra month is usually added every (=co) 3 years).
In Great Britain and Ireland there is an interesting tradition - women can propose (=oświadczyć się) to their beloved (=ukochany) only on leap years. A funny titbit (=ciekawostka) here is that a law passed in 1288 during the reign (=panowanie) of Queen Margaret of Scotland required that a man who turned down (=odrzucić) a proposal of marriage (=oświadczyny) be punished (=ukarany) with a fine - compensation (=zadośćuczynienie) for a woman was established (=określona) as pair of leather gloves, a rose, £1 and a kiss!
Source of the photos: http://en.wikipedia.org/wiki/Leap_year
