Welcome to August, or A Different Kind of Priest Scandal In Rome:
An August 1 history special... The Roman emperor Augustus may have had the messy assassination of his adopted father, Julius Caesar, and the pesky emergence of Jesus of Nazareth on his mind, but it didn't keep him from overlooking a quirk in the calendar. It seems the priests running the official Roman calendar missed the memo saying leap year is every four years, not every three, as they had been doing for decades. So Augustus fixed it by doing nothing--declaring no leap year for 12 years to get the calendar back in sync with Mother Nature's body clock. This act of calendar-calibrating was enough to get a month named after him, as the consuls of the day rechristened the month of Sextilis, and even gave him an extension, stretching the month from 30 days to 31.
http://www.greenheart.com/billh/julian.html