VBA Excel Half of this loop works - vba

Question

So When i run this macro, the A column will be filled with P's and the C column will be filled with 7's, just as I intended it to.
However I also needed the H and I columns to fill with 0's and 1's respectively.
However on the workbook, each worksheet will have the H and I columns unfilled. Only H2 and I2 will be filled. And in some worksheets the H2 and I2 will be the dates (1/0/1900),(1/1/1900) respectively. In other worksheets H2 and I2 will just have a 0 and 1, respectively.
Why is this happening? And why are some of the incorrect columns dates and others are numbers? How can this be fixed?
Dim i As Long
Dim LastRow As Long
For i = 1 To Worksheets.count
With Sheets(i)
LastRow = .Cells(Rows.Count, "A").End(xlUp).Row
.Range("A2:A" & LastRow).Value2 = "P"
LastRow = .Cells(Rows.Count, "C").End(xlUp).Row
.Range("C2:C" & LastRow).Value2 = "7"
LastRow = .Cells(Rows.Count, "H").End(xlUp).Row
.Range("H2:H" & LastRow).Value2 = "0"
LastRow = .Cells(Rows.Count, "I").End(xlUp).Row
.Range("I2:I" & LastRow).Value2 = "1"
End With
Next i

Answer 1

I guess that you have run the code twice and you do not see it changing any more. To see it adding more values every time you run it:
Sub Test()
Dim i As Long
Dim LastRow As Long
For i = 1 To Worksheets.Count
With Sheets(i)
.Columns("A:XFD").NumberFormat = "General"
LastRow = .Cells(Rows.Count, "A").End(xlUp).Row + 1
.Range("A2:A" & LastRow).Value2 = "P"
LastRow = .Cells(Rows.Count, "C").End(xlUp).Row + 1
.Range("C2:C" & LastRow).Value2 = "7"
LastRow = .Cells(Rows.Count, "H").End(xlUp).Row + 1
.Range("H2:H" & LastRow).Value2 = "0"
LastRow = .Cells(Rows.Count, "I").End(xlUp).Row + 1
.Range("I2:I" & LastRow).Value2 = "1"
End With
Next i
End Sub
The problem with (1/0/1900) and (1/1/1900) is that these cells are formatted as date. And 0 is translated to 1/0/1900 and 1 is 1/1/1900. To fix this, in code above the cells are formatted as General with this line:
.Columns("A:XFD").NumberFormat = "General"