It's March, with 1303, 1304, 1306, 1309,

Next month will be 1304, 1305, 1306, 1309.

Further down are 1305, 1306, 1309, 13 12.

As you can see, for non-seasonal months, only one month and next month can be traded, and there are many more trading days in seasonal months than in non-seasonal months!