Dim dHeute As Date = DateTime.Now.Date
Dim dDatum As Date = New Date(2000, 11, 1)
Dim dateDiff As TimeSpan = dDatum - dHeute

Public Class Form1
 
    Dim dt As New cDataTableCSV
 
    Dim bs As New BindingSource
    Dim dgv As New DataGridView With {.Parent = Me, .DataSource = bs, .Top = _
      50, .Width = 464, .Height = 509}
 
 
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Dim sAppPath As String
        sAppPath = Application.StartupPath
        Me.Size = New Size(480, 597)
 
        If Not dt.LoadFile(sAppPath & "\Birthday.csv", _
          System.Text.Encoding.UTF7) Then
            MsgBox("Datei konnte nicht geladen werden")
        Else
            dt.Columns(0).ColumnName = "Name"
            dt.Columns(1).ColumnName = "Geburtstag"
            dt.Columns(2).ColumnName = "Tage"
            dt.Columns(3).ColumnName = "Zeit bis"
            bs.DataSource = dt
        End If
 
    End Sub
End Class

Option Strict On : Option Explicit On : Option Infer Off
Public Class CSV
    Inherits System.Data.DataTable
 
    Public Function LoadFile(ByVal filename As String, _
        ByVal textencoder As System.Text.Encoding, _
        Optional ByVal FeldTrennzeichen As Char = ";"c, _
        Optional ByVal ZeilenTrennzeichen As String = _
        Microsoft.VisualBasic.vbNewLine) As Boolean
 
        Me.Rows.Clear() : Me.Columns.Clear()
        Try
            'Zeilen lesen
            Dim lines() As String = System.IO.File.ReadAllLines(filename, _
              textencoder)
            'Maximale Feldzahl pro Zeile
            Dim fields() As String, maxfields As Integer = 0
            For i As Integer = 0 To lines.GetUpperBound(0)
                If lines(i) <> String.Empty Then
                    fields = lines(i).Split(FeldTrennzeichen)
                    maxfields = System.Math.Max(maxfields, fields.Length)
                End If
            Next i
            If maxfields < 1 Then Return False
 
 
 
            Me.Columns.Add("Name", GetType(String))
            Me.Columns.Add("Geburtstag", GetType(String))
            Me.Columns.Add("Tage", GetType(String))
            Me.Columns.Add("Zeit bis", GetType(String))
 
 
 
            'Datatable: Zeilen füllen
            Dim r As System.Data.DataRow
            For i As Integer = 0 To lines.GetUpperBound(0)
                If lines(i) <> String.Empty Then
                    fields = lines(i).Split(FeldTrennzeichen)
                    System.Array.Resize(fields, maxfields)
                    r = Me.NewRow
                    For k As Integer = 0 To maxfields - 1
                        If String.IsNullOrEmpty(fields(k)) Then
                            r(k) = String.Empty
                        Else
                            r(k) = fields(k).Trim
                        End If
                    Next k 'Felderschleife
                    Me.Rows.Add(r)
                End If
            Next i
            Return Me.Rows.Count > 0
        Catch ex As System.Exception
            Return False
        End Try
    End Function
 
 
 
    Public Sub AddColumn()
        Dim k As Integer = Me.Columns.Count
        'Dim cn As String = "SP_" & CStr(k)
        Dim cn As String = "SP_" & CStr(k)
        Me.Columns.Add(cn, GetType(String))
        For i As Integer = 0 To Me.Rows.Count - 1
            Me.Rows(i).Item(k) = String.Empty
        Next i
    End Sub
End Class

Zitat:

Leider verstehe ich nicht, wie ich beim Start die Datediff einbauen muss, das er den Unterschied berechnet ?

Public Class frmExpressionColumn
 
    Dim WithEvents btnLoad As New Button With _
        {.Parent = Me, .Text = "Laden"}
 
    Dim dt As cDataTableCSV, bs As New BindingSource
 
    Dim dgv As New DataGridView With _
        {.Parent = Me, .Top = 50, .Width = 300, _
         .DataSource = bs, .ColumnHeadersHeight = 40}
 
 
    Private Sub btnLoad_Click(sender As Object, _
                              e As System.EventArgs) Handles btnLoad.Click
 
        If dt IsNot Nothing Then
            'geladene Tabelleninstanz entsorgen
            dt.Clear() : dt.Dispose() : dt = Nothing
        End If
        bs.DataSource = Nothing
 
        dt = New cDataTableCSV
 
        Dim AlterInTagen As String = _
            "AlterInTagen (am " & Today.ToString("dd.MM.yy") & ")"
        Const TageBisGeburtstag As String = "TageBisGeburtstag"
 
        If Not dt.LoadFile _
            ("C:\daten\birthday.csv", System.Text.Encoding.UTF8) Then
 
            MsgBox("Datei konnte nicht geladen werden", MsgBoxStyle.Exclamation)
        Else
            'Spaltenbezeichnung anpassen
            dt.Columns(0).ColumnName = "Name"
            dt.Columns(1).ColumnName = "Geburtstag"
 
            'zusätzliche Spalte
            dt.Columns.Add(AlterInTagen, GetType(Integer))
            dt.Columns(AlterInTagen).AllowDBNull = True
 
            dt.Columns.Add(TageBisGeburtstag, GetType(Integer))
 
            Dim gt As Date
            For i As Integer = 0 To dt.Rows.Count - 1
               If Date.TryParse(dt.Rows(i)("Geburtstag").ToString, gt) Then
                  dt.Rows(i)(AlterInTagen) = _
                  (Today.Date.Ticks - gt.Date.Ticks) / TimeSpan.TicksPerDay
 
                  'nächste Geburtstagsfeier im aktuellen oder im nächsten Jahr 
                  Dim gta As Date = New Date(Today.Year, gt.Month, gt.Day)
                  If gta < Today.Date Then gta = gta.AddYears(1)
 
                  dt.Rows(i)(TageBisGeburtstag) = _
                  (gta.Date.Ticks - Today.Date.Ticks) / TimeSpan.TicksPerDay
                Else
 
                    'ungültiger Eintrag in Spalte Geburtstag
                    dt.Rows(i)(AlterInTagen) = DBNull.Value
                    dt.Rows(i)(TageBisGeburtstag) = DBNull.Value
                End If
            Next i
 
            'Datenbindung erstellen
            bs.DataSource = dt
        End If
 
    End Sub
End Class