A contract month (also known as a delivery month) is the month during which a futures contract expires, and during which delivery may take place according to the terms of the contract.
Each commodity has its own standard contract months. For example, for soybean meal the standard contract months are January, March, May, July, August, September, October and December.
Non-standard contract months (which is any month that is not a standard contract month) are known as serial contract months. That is, it is a month in which no futures contract expires. Accordingly, an option based on a serial contract month will exercise into the nearest standard futures contract. For example, for soybean meal, a February serial option contract will exercise into the March futures contract.