c# - How to add hours to DateTime

DateTime AddHours() Method
The following ASP.NET C# example code demonstrates to us how can we add one or more hours to a DateTime object programmatically at run time. The .Net framework's DateTime AddHours() method returns a new DateTime object that adds the specified number of hours to the value of this instance.

DateTime AddHours() method has a required parameter. This parameter name is value and its data type is a Double. This Double value represents the number of whole and fractional hours. This parameter value can be negative or positive. So, we can also subtract hours from a DateTime object if we pass a negative value as the parameter.

DateTime AddHours() method returns a DateTime object. The return DateTime object is the sum of the DateTime instance and the number of hours passed by the parameter. The fractional part of the value parameter value is the fractional part of an hour. Such as the Parameter value 5.5 is equivalent to 5 hours and 30 minutes.

This method does not change or modify the provided dateTime object instead it returns a new DateTime object which is the result of this operation.
DateTimeAddHours.aspx

<%@ Page Language="C#" %>

<!DOCTYPE html>

<script runat="server">
    protected void Page_Load(object sender, System.EventArgs e) {
        Label1.Text = "Now :" + DateTime.Now.ToString();
    }
    protected void Button1_Click(object sender, System.EventArgs e) {
        DateTime now = DateTime.Now;
        DateTime modifiedDatetime = now.AddHours(6);
        Label1.ForeColor = System.Drawing.Color.OrangeRed;
        Label1.Text ="Now :" + now.ToString();
        Label1.Text += "<br />Your Date Time [after added 6 hours]: " + modifiedDatetime.ToString();

    }
</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title>asp.net date time example: how to add hours (DateTime.Now.AddHours())</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <h2 style="color:Green">asp.net date time example: AddHours()</h2>
        <asp:Label 
             ID="Label1" 
             runat="server" 
             Font-Size="Larger"
             ForeColor="SaddleBrown"
             >
        </asp:Label>
        <br /><br />
        <asp:Button 
             ID="Button1" 
             runat="server" 
             Font-Bold="true" 
             ForeColor="SaddleBrown" 
             OnClick="Button1_Click"
             Text="Add 6 Hours With Now"
             />   
    </div>
    </form>
</body>
</html>