There will be a code at the bottom left or right of the window glass, and there will be a number and several black dots in the penultimate row, representing the production date of the glass.

The number on the code represents the year of production, and the black dot represents the month of glass production.

The production year of glass should be combined with the automobile factory date: for example, the number in the last line of the code is 8, and the automobile factory date is 2007 or 2008, then the production year of glass can be counted as 2008.