According toWikipedia, who explains it better than me:
Ferragosto is an Italian holiday celebrated on August 15. Originally, it may have related to a celebration of the middle of the summer and the end of the hard labour in the fields.
The Catholic Church celebrates this date as a Holy Day of Obligation to commemorate the Assumption of the Virgin Mary the real physical elevation of her sinless soul and incorrupt body, into Heaven. Before the Roman Catholic Church came into existence, however, this holiday was celebrated in theRoman Empire to honor the gods—in particular Diana and the cycle of fertility and ripening.
The present Italian name of the holiday derives from its original Latin name, Feriae Augusti ("Festivals [Holidays] of theEmperor Augustus.
In the past it was common that businesses closed, and the entire month of August was taken as a holiday and leisure time in Italy in honor of this feast day. In present days, Ferragosto is mainly a short holiday (for the ones who are not on longer holiday) when most of Italians take brief vacations at the beach, and enjoy big meals. People celebrate on the streets in many cities of Italy.
The holiday often coincides with peak activity of the Perseid meteor shower, leaving Italians at a particular advantage to view the astral event seen best at pre-dawn hours.