12 BC 12 BC Year 12 BC was either a common year starting on Saturday, Sunday or Monday or a leap year starting on Sunday (link will display the full calendar) of the Julian calendar (the sources differ, see leap year error for further information) and a common year starting on Friday of the Proleptic Julian calendar. At the time, it was known as the Year of the Consulship of Messalla and Quirinius (or, less frequently, year 742 "Ab urbe condita"). The denomination 12 BC for this year has been used since the early medieval period, when the Anno Domini calendar era
Solar Hijri calendar calendar of 365 days for three consecutive years plus an extra day in the next year, save for exceptions to the latter in three out of every four centenaries). The start of the year and its number of days remain fixed to one of the two equinoxes, the astronomically important days which have the same duration of the sun. It results in less variability of all celestial bodies comparing a specific calendar date from one year to others. Each of the twelve months corresponds with a zodiac sign. The first six months have 31 days, the next five have 30