Why My Month Code Macro Results In Error

Here is my Macro:

Sub monthdatecoding()

Dim lastrow As Long, t As Long
lastrow = ActiveSheet.UsedRange.Rows.Count
For t = lastrow To 1 Step -1

'June
If Cells(t, 1).Value "" Then
If Left(Cells(t, 13).Value, 2) = "6/" Then Cells(t, 41).Value = "June"
End If

'July
If Cells(t, 1).Value "" Then
If Left(Cells(t, 13).Value, 2) = "7/" Then Cells(t, 41).Value = "July"
End If