Как программно получить количество високосных годов за промежуток времени?

Public Class Form1
    
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim a As Date
        a = CDate(TextBox1.Text) ' "01.01.2000"
        ' TextBox2 = "05.03.2015 "
 
        MsgBox(Date.IsLeapYear(a.Year))
 
    End Sub
 
End Class

        Dim Date1 As Date = "01.01.2000"
        Dim Date2 As Date = "05.03.2015"
        Dim S As String = ""
        Do While Date1 < Date2
            If Date.IsLeapYear(Date1.Year) Then S &= Date1.Year & vbCrLf
            Date1 = Date1.AddYears(1)
        Loop
        MsgBox(S)

Public Class Form1
 
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        CheckedListBox1.Items.Clear()
        For i = 0 To DateTimePicker2.Value.Year - DateTimePicker1.Value.Year
            If Date.IsLeapYear(DateTimePicker1.Value.Year + i) = True Then CheckedListBox1.Items.Add(DateTimePicker1.Value.Year + i)
        Next
    End Sub
End Class

        Dim Date1 As Date = "01.01.2000"
        Dim Date2 As Date = "05.03.2015"
        Dim Cnt As Integer = 0
        Do While Date1 < Date2
            If Date.IsLeapYear(Date1.Year) Then Cnt += 1
            Date1 = Date1.AddYears(1)
        Loop
        MsgBox(Cnt)