Calculate Quarter from given Date in ASP.Net using C# and VB.Net

Hi ramco1917,

Please refer below sample.

HTML

<asp:TextBox ID="txtDate" runat="server" Text="01/10/2022" />
<asp:Button Text="Select" runat="server" OnClick="Select" />
<hr />
<asp:GridView ID="gvQuarters" runat="server" AutoGenerateColumns="false">
<Columns>
    <asp:BoundField DataField="Quarter" HeaderText="Quarters" />
    <asp:BoundField DataField="Start" HeaderText="Start Date" DataFormatString="{0:dd-MM-yyyy}" />
    <asp:BoundField DataField="End" HeaderText="End Date" DataFormatString="{0:dd-MM-yyyy}" />
</Columns>
</asp:GridView>

Namespace

C#

using System.Data;

VB.Net

Imports System.Data

Code

C#

protected void Select(object sender, EventArgs e)
{
    DateTime dt = Convert.ToDateTime(txtDate.Text);
    DateTime startDay = new DateTime(dt.Year, dt.Month, 1);
    DateTime endDay = startDay.AddMonths(3).AddDays(-1);
    DataTable dtQuarters = new DataTable();
    dtQuarters.Columns.Add("Quarter");
    dtQuarters.Columns.Add("Start", typeof(DateTime));
    dtQuarters.Columns.Add("End", typeof(DateTime));
    dtQuarters.Rows.Add("Quarter 1", startDay, endDay);
    endDay = endDay.AddDays(1);
    dtQuarters.Rows.Add("Quarter 2", endDay, endDay.AddMonths(3).AddDays(-1));
    endDay = endDay.AddMonths(3).AddDays(-1).AddDays(1);
    dtQuarters.Rows.Add("Quarter 3", endDay, endDay.AddMonths(3).AddDays(-1));
    endDay = endDay.AddMonths(3).AddDays(-1).AddDays(1);
    dtQuarters.Rows.Add("Quarter 4", endDay, endDay.AddMonths(3).AddDays(-1));
    gvQuarters.DataSource = dtQuarters;
    gvQuarters.DataBind();
}

VB.Net

Protected Sub Select(ByVal sender As Object, ByVal e As EventArgs)
    Dim dt As DateTime = Convert.ToDateTime(txtDate.Text)
    Dim startDay As DateTime = New DateTime(dt.Year, dt.Month, 1)
    Dim endDay As DateTime = startDay.AddMonths(3).AddDays(-1)
    Dim dtQuarters As DataTable = New DataTable()
    dtQuarters.Columns.Add("Quarter")
    dtQuarters.Columns.Add("Start", GetType(DateTime))
    dtQuarters.Columns.Add("End", GetType(DateTime))
    dtQuarters.Rows.Add("Quarter 1", startDay, endDay)
    endDay = endDay.AddDays(1)
    dtQuarters.Rows.Add("Quarter 2", endDay, endDay.AddMonths(3).AddDays(-1))
    endDay = endDay.AddMonths(3).AddDays(-1).AddDays(1)
    dtQuarters.Rows.Add("Quarter 3", endDay, endDay.AddMonths(3).AddDays(-1))
    endDay = endDay.AddMonths(3).AddDays(-1).AddDays(1)
    dtQuarters.Rows.Add("Quarter 4", endDay, endDay.AddMonths(3).AddDays(-1))
    gvQuarters.DataSource = dtQuarters
    gvQuarters.DataBind()
End Sub

Screenshot