During the period covered in this book, the new year in Florence started on March 25 at the feast of Annunciation—exactly nine months before Christmas. When necessary, I use the designation ab incarnatione to indicate the disparity with the modern calendar. In Venice, the new year started on March 1, and the discrepancy is marked by the phrase more veneto (m.v.). Obviously, all dates before 1582 follow the Julian calendar and need to be further readjusted in order to comply with the current way of timekeeping established by the Gregorian reform.
Similarly, the new day during the period addressed in this volume started when the sun sank below the horizon, and the hours of the day mentioned in historical documents were counted from this moment. When needed, I converted them using solar calculators that allow us to assess the time of sunset and sunrise for a particular geographic location throughout the year. In order to avoid further confusion, I subsequently prefer using expressions such as before/after the sunset or sunrise instead of just stating the hour of the day in the modern sense.
The leading regional states in late medieval and Renaissance Italy, which are at the center of my empirical narrative, relied on bimetallic monetary systems based on silver and gold coins. Their mutual exchange rates varied over time, depending upon the relative values of both metals. However, currencies based on gold were notably more stable and represent monetary values that are easier to compare across various times and geographies since the three main denominations—the Florentine florin (coined as of 1252), Venetian ducat (1284), and ultimately the Roman scudo (after 1530)—contained almost an equal amount, about 3.5 grams of pure gold. Under Francesco I Sforza, Milan de facto adopted the florin as well because the new duke’s main financial adviser and banker was Cosimo de’ Medici. This is clearly reflected in the ducal accounting books, which were kept not only in the local currency, imperial liras, but at times also in florins.
This is the main reason why, whenever it was possible, I converted all monetary values discussed in this volume into one of the three currencies based on gold: florins, ducats, or scudi. I use their values practically interchangeably, deliberately ignoring slight differences among their mutual exchange rates in a particular historical moment.