.net calculate timespan in hours and minutes c# vb.net

OK

Thanks

The requirement is that I have a set number of hours and minutes eg; 01.30 and I need to multiply this by an integer  

so 01:30 * 4 for example

Try This

			DateTime dtStart = DateTime.Parse(StartTime.Text);
			DateTime dtEnd = DateTime.Parse(EndTime.Text);
			TimeSpan ts = dtEnd.Subtract(dtStart);
 
			/* calculate time with half hour */
			DateTime time = new DateTime(ts.Ticks);
			string strFormatedTime = time.AddSeconds(ts.TotalSeconds * 4).ToString("hh:mm");

                                              

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Hi!
A little quick but now it formats output as time

Matti

 Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim dtStart, dtEnd, ts
 
        dtStart = DateTime.Parse(StartTime.Text)
        dtEnd = DateTime.Parse(EndTime.Text)
 
        ts = DateDiff("n", dtStart, dtEnd) ' in case you need it in minutes
 
 
        ts = ts * 4
        ts = ts / 60
        ts = Format(ts, "00.00")
        ts = Replace(ts, ",", ":", 1, 1, CompareMethod.Text)
        MsgBox(ts)
    End Sub

                                              

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OK thanks but I am not getting the correct calculation

Up to this point here is fine

                DateTime dtStart = DateTime.Parse(txtClassStartTime.Text);
                DateTime dtEnd = DateTime.Parse(txtClassEndTime.Text);
                TimeSpan ts = dtEnd.Subtract(dtStart);

Now say starttime was 0900am and end time 1130am - this gives 2 hours 30 minutes.  Now I want to calculate this 2 hours 30 minutes by say 2; now this would be a total of 5 hours.  This is what I need.

Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim dtStart, dtEnd, ts

        dtStart = DateTime.Parse(StartTime.Text)
        dtEnd = DateTime.Parse(EndTime.Text)

        ts = DateDiff("n", dtStart, dtEnd) ' in case you need it in minutes


        ts = ts * 2
        ts = ts / 60
        ts = Format(ts, "00.00")
        ts = Replace(ts, ",", ":", 1, 1, CompareMethod.Text)
        MsgBox(ts)
    End Sub

Can I use this in asp.net ?  What namespace to I need to get hte datetdiff?

Hi!

Public Function DateDiff(ByVal Interval As Microsoft.VisualBasic.DateInterval, ByVal Date1 As Date, ByVal Date2 As Date, Optional ByVal DayOfWeek As Microsoft.VisualBasic.FirstDayOfWeek = Sunday, Optional ByVal WeekOfYear As Microsoft.VisualBasic.FirstWeekOfYear = Jan1) As Long

Namespace Microsoft.VisualBasic

Matti

HI Sorry

I cannot use that as I am using c# with asp.net

I have been told I must do it something like the previous comment like this

                        DateTime time = new DateTime(ts.Ticks);
                        string strFormatedTime = time.AddSeconds(ts.TotalSeconds * 2).ToString("hh:mm");

However it gives wrong result.  If the time span is 2.5 hours and multiplied by 2 it gives result as 7.30 and not 5

sorry . it's my mistake (  im added two times)

change code to.....
string strFormatedTime  = time.AddSeconds(ts.TotalSeconds * (N-1)).ToString("hh:mm");

ie ...  string strFormatedTime  = time.AddSeconds(ts.TotalSeconds * (2-1)).ToString("hh:mm");

Thanks

But I figured it out!

This works great

        ts = TimeSpan.FromTicks(ts.Ticks * 2);

Now how can I convert ts to a float?

i think no direct method

Convert.ToDouble(ts.Hours.ToString() + "." + ts.Minutes.ToString())

Hi!

If it's a ASP.NET then you can use VB.NET code in a VB.NET component and warp the VB.NET code in a function in it.
The it does not matter if you buld this in #C In ASP.NET

Matti