This tip computes how many rows with dates 2 months before today in a
datatable
This sample needs only a datagridview and a label on a form
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles MyBase.Load
Dim dt As New DataTable
dt.Columns.Add("Count", GetType(System.Int32))
dt.Columns.Add("Date", GetType(System.DateTime))
For i As Integer = 0 To 5
Dim dtime As DateTime = Now.AddMonths(-i + 3)
dt.LoadDataRow(New Object() _
{DateTime.DaysInMonth(dtime.Year, dtime.Month), dtime}, True)
Next
DataGridView1.DataSource = dt
' This is the sample
Dim ThisDate As String = Now.ToString("#MM/dd/yy#")
ThisDate = ThisDate.Replace("-", "/")
Label1.Text = dt.Compute("Sum(Count)", "Date < " _
& ThisDate).ToString
End Sub
End Class