October (Roman month) October (Roman month) October (from Latin "octo", "eight") or mensis October was the eighth of ten months on the oldest Roman calendar. It had 31 days. October followed September (from "septem", "seven") and preceded November ("novem", "nine"). After the calendar reform that resulted in a 12-month year, October became the tenth month, but retained its numerical name, as did the other months from September through December. Some of the observances in October marked the close of the season for military campaigning and farming, which commenced in March ("Martius", "Mars' month"). October was under the guardianship "(tutela)" of Mars. The Romans
Delivery month futures exchanges (such as bonds, short-term interest rates, foreign exchange and US stock indexes) tend to expire quarterly, in March, June, September and December. For financial contracts traded on non-US futures exchanges, the expiration schedule may not be quarterly. This table lists the conventional letter codes used in tickers to specify delivery month: To name a specific contract in a financial futures market, the month code will follow the contract code, and in turn be followed by the year. For example, CLZ3 is the December 2023 NYMEX crude oil contract. CL denotes crude oil (crude light), Z corresponds to the