Run-Time Error '1004': Application Defined or Object-Defined Error - excel

Question

I am trying to copy and paste data from one sheet to the next from a selected range entered by the user. TxtDateStart takes the start date, and TxtDateEnd takes the end date. Then it would copy and paste the data from the range of dates to a new sheet.
When I run the code in a form, it works but I rather have the form call the module. This is where I get the run-time error. I'm no expert in VBA, help would be appreciated.
The sheet where the data is is called Unit2Data, and the sheet i want to paste the data is Graphing Sheet.
The error occurs in this line
Sheets("Unit2Data").Range(Cells(i, 1), Cells(i, 73)).Select
Sub Unit2Data()
Dim lrow As Long, i As Long, x As Date, y As Date, erow As Long
x = TxtDateStart
y = TxtDateEnd
'Find the Last Row of Sheet1
lrow = Sheets("Unit2Data").Range("A" & Rows.Count).End(xlUp).Row
'start counting from row 3 to last row
For i = 4 To lrow
' Date value converted as numeric value by multiplying with number 1
If Cells(i, 1) * 1 >= x * 1 Then
If Cells(i, 1) * 1 <= y * 1 Then
'If above conditions matched then select the matched range/ entire column
Sheets("Unit2Data").Range(Cells(i, 1), Cells(i, 73)).Select
'copy the selected row
Selection.Copy
'to make sheet2 active where we want to paste the selected row
Sheets("Graphing Sheet").Activate
'to find the empty row from where the copied row of sheet1 to be pasted in sheet2
erow = Cells(Rows.Count, 1).End(xlUp).Offset(1, 0).Row
'to activate or select the empty row of sheet2
ActiveSheet.Cells(erow, 1).Select
'paste the copied data
ActiveSheet.Paste
'to deselect the copy and selected mode
Application.CutCopyMode = False
'for above the if we need 3 end if to close if conditions
End If
End If
'to activate sheet1 for searching the matched data
Sheets("Unit2Data").Activate
'continue for look until above matched found
Next i
End Sub
Date Data
01/01/2019 2
02/02/2019 3

Answer 1

First you should avoid using Select in VBA. There, almost always, are better ways to achieve whatever you are using Select for.
In your case, and regarding only the specific error/question raised, delete the error-causing line and the next line (Selection.Copy) and replace with this:
With Sheets("Unit2Data")
.Range(.Cells(i, 1), .Cells(i, 73)).Copy
End With
Rewriting your entire code to avoid using Select:
Sub Unit2Data()
Dim lrow As Long, i As Long, x As Date, y As Date, erow As Long
x = TxtDateStart
y = TxtDateEnd
With Sheets("Unit2Data")
lrow = .Range("A" & .Rows.Count).End(xlUp).Row
For i = 4 To lrow
If .Cells(i, 1) * 1 >= x * 1 Then
If .Cells(i, 1) * 1 <= y * 1 Then
With Sheets("Graphing Sheet")
erow = .Cells(.Rows.Count, 1).End(xlUp).Offset(1, 0).Row
End With
.Range(.Cells(i, 1), .Cells(i, 73)).Copy _
Destination:= Sheets("Graphing Sheet").Cells(erow, 1)
End If
End If
Next i
End With
End Sub