Add 1 to a number from the worksheet before it

Hello Excel Guru's

I have 3 Tabs (will be more – once I get some help with a workable formula) - Feb, Mar and April

On the Feb tab you will see 5 columns with number shift rotations

On the Mar tab I want to refer to the Feb Tab same column and add 1 to the rotation number.

I can do this by simplifying pointing back to the Feb sheet and then do a + 1.
But the problem is when I get to 30 and it adds 1 it goes to 31 which is not a shift rotation.

I have highlighted on the Feb tab see test workbook what is happening when I use the simple + 1
How can I get the same result every time I refer back to the previous sheet but having the 31 be 6

The Apr tab refers back to the Mar tab.
The Mar tab shows the desired output I am looking for

Long Story short .. each tab will refer the previous and Add 1 to the number except for if the cell is referring to 30 I need it to go back to 6.

Let me know if you have any questions and Thanks in advance.