From The Art and Popular Culture Encyclopedia
In common years no other month starts on the same day of the week as August, though in leap years February starts on the same day. August ends on the same day of the week as November every year.
This month was originally named Sextilis in Latin, because it was the sixth month in the original ten-month Roman calendar under Romulus in 753 BC, when March was the first month of the year. About 700 BC it became the eighth month when January and February were added to the year before March by King Numa Pompilius, who also gave it 29 days. Julius Caesar added two days when he created the Julian calendar in 45 BC giving it its modern length of 31 days. In 8 BC it was renamed in honor of Augustus (despite common belief, he did not take a day from February; see the debunked theory on month lengths). According to a Senatus consultum quoted by Macrobius, he chose this month because it was the time of several of his great triumphs, including the conquest of Egypt.