Caesar Augustus is perhaps best-known to readers of the Holy Bible from the very famous census that caused Jesus Christ to be born in Bethlehem. Augustus' name is however also widely known from the pagan-based Roman calendar that is in common use in the world today. The month of August was named after Caesar Augustus.
Known to the Romans as Januarius, it was named after Janus, the Roman pagan god of doorways and beginnings.
Known to the Romans as Februarius, it was named from Februa, a pagan "purification" festival held during the month.
Known to the Romans as Martius, it was named from the Roman god Mars.
Known to the Romans as Aprilis, it was named after the goddess Venus, also known as Aphrodite.
Known to the Romans as Maius, it was named after the goddess Maia.
Known to the Romans as Junius, it was named after the Roman goddess Juno.
Originally known as Quintilis on the Roman calendar, it was renamed Julius after Julius Caesar.
Originally known as Sextilus, it was renamed Augustus after Caesar Augustus.
September is named from the Latin word septem, meaning seven i.e. before the Romans changed it, their calendar began in March i.e. spring in the northern hemisphere. April was the second month (now it's the fourth), May was the third month (now it's the fifth) etc. and September was the seventh month (now it's the ninth).
October is named from the Latin word octo, meaning eight. As explained above, the Roman calendar later shifted ahead 2 months. October, meaning the eighth month, became the tenth month, as it is today.
November is named from the Latin word novem, meaning nine. November was originally the ninth month of the Roman calendar, now it's the eleventh.
December is named from the Latin word decem, meaning ten. Again, as explained above, December was originally the tenth month of the Roman calendar.
To understand how God's nature-based calendar (although commonly called the "Jewish calendar," God's calendar began at creation, long before there were any Jews) differs from the pagan Roman calendar, see The Bible Calendar and