Day duration calculation

[Nzsquall]

Hi, I am a C# beginner, can somebody tells me how to code in the value-changed event of the DateTimePicker control so that it can accept two dates and calculates the difference between them? For example, the duration day between now and any day changed in the daytimepicker?

Thanks in advance

[whodgson]

Google julian day + date.
Its relatively straight forward to write a function to convert a Gregorian date to a Julian date. The period between the two Julian dates and fractions of days constitutes the rquired period to a precision of seconds if needed.

[Nzsquall]

Thanks. But I am thinking of writing this code to see whether it works

private void dateTimePicker_ValueChanged(object sender, EventArgs e)
        {
          
            int firstMeetingDate = int.Parse(dateTimePicker.Text);

            //how can I capture the system current time as an integer?
            //and the requirement said that I should return the int value
            //as day, the format in my daytimePicker is ("week,dd,mm,year)
            //how can I just capture the day and calculate the duration between 
            //them?       
        }

Many thanks

[GaryTexmo]

//how can I capture the system current time as an integer?

I think...

DateTime.Now.Ticks

... is what you're looking for.

The DateTime class has lots of stuff to do with time. Here's the MSDN page...

http://msdn.microsoft.com/en-us/library/system.datetime.aspx

[Plater]

A DateTimePicker can only contain a single datetime value at a time, however you can keep track of them.
Use the .Value property of it, rather the the .Text. This will return a DateTime object that you can use to caompare against DateTime.Now

[Nzsquall]

Hi, I have try
private void dateTimePicker_ ValueChanged(ob ject sender, EventArgs e)
{
DateTime fistMeetingDate = dateTimePicker. Value;
DateTime currentDate = DateTime.Now;
TimeSpan duration= currentDate - fistMeetingDate ;
durationTextBox .Text = duration.ToStri ng();
}
But it appear a very strange String, for instance, today is "Tuesday, 6 October 2009", then I pick firstMeetingDat e in the dateTimePicker to "Tuesday, 1 October 2009", the result in the durationTextBox is "5.00:00:57.926 9310". How can I get a int day value?
Thanks in advance.

[whodgson]

Parse the string and extract the first digit/s before the dot
The string format you show is day.hr:m:s.

[Plater]

Make it say duration.TotalD ays.ToString()
That will give you the timespan in terms of whole and fractional days (so 36 hours would give a value of 1.5 days)

Remember to check MSDN on the objects if you are having troubles, its a good resource