VBA using DateSerial stops at blank cell in range - vba

Question

I have some vba code that evaluates 6 columns and formats the dates from yyyymmdd to mm/dd/yyyy. The code works fine until it finds a blank cell within the range and then I get a type 13 Run time error. The debugger highlights the DateSerial line so I assume thats where my issue is.
Any thoughts?
Sub Convert_Date()
Dim c As Range
Application.ScreenUpdating = False
For Each c In Range("AC2:AC" & Cells(Rows.Count, "AC").End(xlUp).Row)
c.Value = DateSerial(Left(c.Value, 4), Mid(c.Value, 5, 2), Right(c.Value, 2))
c.NumberFormat = "mm/dd/yyyy"
Next
Application.ScreenUpdating = False
Dim b As Range
Application.ScreenUpdating = False
For Each b In Range("AL2:AL" & Cells(Rows.Count, "AL").End(xlUp).Row)
b.Value = DateSerial(Left(b.Value, 4), Mid(b.Value, 5, 2), Right(b.Value, 2))
b.NumberFormat = "mm/dd/yyyy"
Next
Application.ScreenUpdating = False
Dim a As Range
Application.ScreenUpdating = False
For Each a In Range("AQ2:AQ" & Cells(Rows.Count, "A").End(xlUp).Row)
a.Value = DateSerial(Left(a.Value, 4), Mid(a.Value, 5, 2), Right(a.Value, 2))
a.NumberFormat = "mm/yyyy"
Next
Application.ScreenUpdating = False
Dim d As Range
Application.ScreenUpdating = False
For Each d In Range("AR2:AR" & Cells(Rows.Count, "A").End(xlUp).Row)
d.Value = DateSerial(Left(d.Value, 4), Mid(d.Value, 5, 2), Right(d.Value, 2))
d.NumberFormat = "mm/yyyy"
Next
Application.ScreenUpdating = False
Dim e As Range
Application.ScreenUpdating = False
For Each e In Range("AT2:AT" & Cells(Rows.Count, "A").End(xlUp).Row)
e.Value = DateSerial(Left(e.Value, 4), Mid(e.Value, 5, 2), Right(e.Value, 2))
e.NumberFormat = "mm/yyyy"
Next
Application.ScreenUpdating = False
Dim f As Range
Application.ScreenUpdating = False
For Each f In Range("AU2:AU" & Cells(Rows.Count, "A").End(xlUp).Row)
f.Value = DateSerial(Left(f.Value, 4), Mid(f.Value, 5, 2), Right(f.Value, 2))
f.NumberFormat = "mm/yyyy"
Next
Application.ScreenUpdating = False
End Sub

Answer 1

Try to make a check around each condition, whether the value is not empty. Like this:
If Not IsEmpty(c) then
c.Value = DateSerial(Left(c.Value, 4), Mid(c.Value, 5, 2), Right(c.Value, 2))
c.NumberFormat = "mm/dd/yyyy"
End If
Once you get deeper into VBA, you may start using functions like this:
Sub Convert_Date()
Application.ScreenUpdating = False
RockAndRoll "AC2:AC", "AC"
Call RockAndRoll ("AR2:AR", "A")
RockAndRoll "AL2:AL", "AC"
'RockAndRoll etc...
Application.ScreenUpdating = True
End Sub
Public Sub RockAndRoll(myLeft As String, myRight As String)
Dim a As Range
With ActiveSheet
For Each a In .Range(myLeft & .Cells(.Rows.Count, myRight).End(xlUp).Row)
If Not IsEmpty(a) Then
a.value = DateSerial(Left(a.value, 4), Mid(a.value, 5, 2), Right(a.value, 2))
a.NumberFormat = "mm/yyyy"
End If
Next
End With
End Sub
So you should not be repeating the code over and over again.