(By Kate Carlisle)Pisa, March 13 - Pisans are unique in many ways. First, they are known for a large tower that looks like it should have toppled centuries ago, but instead has become a UNESCO World Heritage site. Their sometimes 'prickly' character and fame for numerous wars and raids as a historic maritime republic has earned them a saying among their Tuscan counterparts - 'Meglio un morto in casa che un pisano alla porta' or 'Better a dead person in your house than a Pisan at your door'. Ancient rivalries die hard in modern Italy. And just to make sure that the dividing lines from their Tuscan neighbors are cultural, time-related, as well as geographic, Pisa even has its own way of calculating the year. Since the 10th century, Pisans have celebrated their New Year on March 25, to coincide with the day of the Annunciation of the Virgin Mary (and thus the incarnation of Jesus), nine months before December 25. The Pisan calendar, dating back to 985, was also briefly used in the cities of Padua and Milan where the former republic wielded strong influence through commerce, trade and sometimes warfare. In 1749, the Grand Duke of Tuscany decided to unite the region under one calendar, and chose the Gregorian one - something that Pisans chose to ignore...at least off the books. For Pisans, having their own unique calendar was another sign of its embattled hold on power. Eventually, the Pisan New Years celebrations went underground, then disappeared altogether. But in 1999 a historical society rediscovered archives detailing food and traditions surrounding the March 25th celebration and Pisans embraced their festival once again. The revived holiday has come to represent the kick-off to the city's tourist season and events stretch over several days, sometimes a full week. In 2012, 40,000 visitors from outside of Italy celebrated with the city's inhabitants on the Field of Miracles, the city's monumental center where the Leaning Tower, Cathedral and Baptistry are located. With Ryanair flights arriving daily to the nearby Pisa International airport, the city is easily accessible from more than 70 destinations across Europe. The celebration traditionally starts at 12 noon inside the splendid masterpiece of Romanesque architecture, the Cathedral (Duomo di Pisa), when a ray of sunlight penetrates a round nave window, illuminating a marble egg on a shelf next to the pulpit of Giovanni Pisano. With a procession full of pomp and ceremony for Pisans and onlookers alike, the Pisan New Year has begun.