In adding the new days to the calendar, Caesar tried to disturb the separation between festivals as little as possible (relative to the Kalends system of dating), and the new days were actually added just before the last day of each month that was extended, except for April, where it was inserted between the 6th and 5th Kalends. The month of July (Julius, from earlier Quinctilis) got its name in 44 BCE by decree of the senate. Notice that while our general rule for converting days of the month still applies, the Kalends numbering in the lengthened months is different in the Julian and Republican calendars. E.g., December 25 = vi kal Jan. in the Republican, but viii kal. Jan. in the Julian.
