The difference between glass futures 30 1 and 50 1 is that the contract expires in different months.

30 1 stands for the glass futures contract due in June 2023, 5438+0, and 305 stands for the glass futures contract due in May 2023. The last two digits of the combination of year and month are used in general production trading software, such as 230 1, 2305 and 2309, and there are also the last two digits of the combination of year and month, namely 30659.