There are many results. Whether the calendar is 7 days a week or 10 days is different.

What is the truth? 76/4= 19? The intersection of the diagonal lines of the four corners is 19,

10 day, 8, 18, 10, 30, none 3 1.

7 days can be 1 1, 13, 25, 27; 10, 14,24,28 ; 9, 15,23,29 ,

This is the most common situation, that is, the number 19 is right in the middle of the calendar. If it is on the side, it will be gone.