DateAdd function shows date from 1900

[olorin_117]

I have run to this weird problem and I really can't understand what is happening.

I have the code below

Dim tddate As Date
Dim expdate As String
Dim inputdate As String

tddate = Worksheets("Sheet3").Range("pdate").Value
inputdate = TextBox1.Value
expdate = Format(DateAdd("m", 18, tddate), "dd/mm/yyyy")

If inputdate = expdate Then
Range("A1").Value = TextBox1.Value
Else
MsgBox "Input the correct date"
Cancel = True
End If

It compares the user input with the date that MUST be in a textbox...Until yesterday it worked PERFECT with no problems at all

Today that I continued my work on the excel project If I Debug.Print the expdate varieable the date that it shows is 30/06/1901 !!!!!!

PS. If I Debug.Print Now it shows the correct date
PS.2. I am using Excel 2019 but I tried the workbook on a different laptop with Excel 2016 and shows the same thing. (The second try is because I changed my RAM yesterday -every time in my system is correct - and thought I messed up something)

 

[dmt32]

Hi,
see if this update to your code does what you want

    Dim tddate      As Date, expdate As Date
    Dim inputdate   As Variant
   
    inputdate = TextBox1.Value
    If Not IsDate(inputdate) Then Exit Sub Else inputdate = DateValue(inputdate)
   
    tddate = Worksheets("Sheet3").Range("pdate").Value
   
    expdate = DateAdd("m", 18, tddate)
   
    If inputdate = expdate Then
        With Range("A1")
            .Value = inputdate
            .NumberFormat = "dd/mm/yyyy"
        End With
    Else
        MsgBox "Input the correct date", 48, "Invalid Date Entry"
        Cancel = True
    End If

Dave