Suppose that you have two date time values one is startdate and second is EndDate, and you want to calculate time interval between both dates ,in this situation we can use timespan object like this:

*(According to MSDN: A TimeSpan object represents a time interval (duration of time or elapsed time) that is measured as a *

*positive or negative number of days, hours, minutes, seconds, and fractions of a second. The*

**TimeSpan**structure can also be used to represent the time of day, but only if the time is unrelated to a particular date. Otherwise, the DateTime or DateTimeOffset structure should be used instead.)before starting of code

VB.Net

- Dim StartTime As DateTime = #6/12/2008 3:09:00 PM#
- Dim EndTime As DateTime = #6/10/2008 12:04:00 PM#
- Dim TimeDiff As TimeSpan = EndTime.Subtract(StartTime)
- Dim Days As Integer = TimeDiff.ToatlDays
- 'calculate Value of Days Component
- Dim Minutes As Integer = TimeDiff.TotalMinutes
- 'calculate Value of Minutes Component
- Dim Seconds As Integer = TimeDiff.TotalSeconds
- 'calculate Value of Seconds Component
- Dim TotalDays As Integer = TimeDiff.TotalDays
- 'calculate Value of Total Days
- Dim TotalHours As Integer = TimeDiff.TotalHours
- 'calculate Value of Total Minutes
- Dim TotalSeconds As Integer = TimeDiff.TotalSeconds
- 'calculate Value of Total Seconds

we can use subtract method for calculating difference between two date like :

- TimeDiff = EndTime.Subtract(StartTime)

Add a day, a month and a year to a Date

- Dim FirstDate As Date
- Dim SecondDate As Date
- FirstDate = #2/28/2010#
- 'Add a day
- SecondDate = FirstDate.AddDays(1)
- 'Add some months
- SecondDate = FirstDate.AddMonths(6)
- 'Subtract a year
- SecondDate = FirstDate.AddYears(-1)</blockquote>

[C#]

- DateTime StartTime = 12/06/2008 15:09:00;
- DateTime EndTime = 10/06/2008 12:04:00;
- TimeSpan TimeDiff = EndTime.Subtract(StartTime);
- int Days = TimeDiff.ToatlDays;
- //calculate Value of Days Component
- int Minutes = TimeDiff.TotalMinutes;
- //calculate Value of Minutes Component
- int Seconds = TimeDiff.TotalSeconds;
- //calculate Value of Seconds Component
- int TotalDays = TimeDiff.TotalDays;
- //calculate Value of Total Days
- int TotalHours = TimeDiff.TotalHours;
- //calculate Value of Total Minutes
- int TotalSeconds = TimeDiff.TotalSeconds;
- //calculate Value of Total Seconds
- //we can use subtract method for calculating difference between two date like :
- TimeDiff = EndTime.Subtract(StartTime);

Add a day, a month and a year to a Date

- System.DateTime SecondDate = default(System.DateTime);
- FirstDate = 28/02/2010 00:00:00;
- //Add a day
- SecondDate = FirstDate.AddDays(1);
- //Add some months
- SecondDate = FirstDate.AddMonths(6);
- //Subtract a year
- econdDate = FirstDate.AddYears(-1);