Calculate Time Difference Between DateTime Objects

To get time difference you need to use TimeSpan object, with code like this:

TimeSpan ts = DateTime1 - DateTime2;

For example, if you want to calculate time difference between server time and UTC time:

[ C# ]

protected void Page_Load(object sender, EventArgs e)
{
    // Declare and get DateTime values
    DateTime StartDate = System.DateTime.Now;
    DateTime EndDate = System.DateTime.UtcNow;
 
    // Find time difference between two dates
    TimeSpan TimeDifference = StartDate - EndDate;
 
    // Write difference in hours and minutes
    Response.Write("Time difference between server time and Coordinated Universal Time (UTC) is " + 
        TimeDifference.Hours.ToString() + " hours ");
    if (TimeDifference.Minutes != 0)
        Response.Write(" and " + TimeDifference.Minutes.ToString() + " minutes.");
 
}

http://www.beansoftware.com/ASP.NET-FAQ/DateTime-TimeSpan.aspx