46 BC 46 BC Year 46 BC was the last year of the pre-Julian Roman calendar. At the time, it was known as the Year of the Consulship of Caesar and Lepidus (or, less frequently, year 708 "Ab urbe condita"). The denomination 46 BC for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. This year marks the change from the pre-Julian Roman calendar to the Julian calendar. The Romans had to periodically add a leap month every few years to keep the calendar year in
Leap year Leap year A leap year (also known as an intercalary year or bissextile year) is a calendar year containing one additional day (or, in the case of lunisolar calendars, a month) added to keep the calendar year synchronized with the astronomical or seasonal year. Because seasons and astronomical events do not repeat in a whole number of days, calendars that have the same number of days in each year drift over time with respect to the event that the year is supposed to track. By inserting (also called "intercalating") an additional day or month into the year, the drift can