C# Multiple Time Duration Calculation

Question

Hi, i have a problem here which is my output for my calculation is wrong.   I have 4 dateTimePicker using custom format as HH:mm named dtpIn1, dtpOut1, dtpIn2, dtpOut2 . My target calculation are duration between dtpOut1 to dtpIn1 , duration between dtpOut2 to dptIn2 and total duration between dtpOut1 to dtpIn2 .   I got right output on calculation dtpOut1 to dtpIn1 and dtpOut1 to dtpIn2 and got very wrong on dtpOut2 to dtpIn2. What is wrong with my code here? Can you guys help me?   Here's my code :   //Calculation for time total and time sum start private void dtpIn1_ValueChanged(object sender, EventArgs e) { TimeSpan result = this.dtpIn1.Value - this.dtpOut1.Value; this.txtTotal1.Text = result.ToString(); } private void dtpOut2_ValueChanged(object sender, EventArgs e) { TimeSpan result = this.dtpIn2.Value - this.dtpOut2.Value; this.txtTotal2.Text = result.ToString(); } private void dtpIn2_ValueChanged(object sender, EventArgs e) { TimeSpan result = this.dtpIn2.Value - this.dtpOut1.Value; this.txtSum.Text = result.ToString(); } //Calculation for time total and time sum end

Tapan Patel · Accepted Answer

It is difficult to fix your issue without looking at your code but take a look at below working example.   private   void  dtpTI1_ValueChanged( object  sender, EventArgs e)   {       txtBetweenFirstSet.Text =  new  TimeSpan(Math.Abs(dtpTO1.Value.Ticks - dtpTI1.Value.Ticks)).ToString();   }      private   void  dtpTI2_ValueChanged( object  sender, EventArgs e)   {       txtBetweenSecondSet.Text =  new  TimeSpan(Math.Abs(dtpTO2.Value.Ticks - dtpTI2.Value.Ticks)).ToString();       txtOverall.Text =  new  TimeSpan(Math.Abs(dtpTO1.Value.Ticks - dtpTI2.Value.Ticks)).ToString();   }    first datetimepicker is dtpTO1 and next one is dtpTI1. (textbox-txtBetweenFirstset in between shows time difference expected for first timeout and first time in.)

Shafiqq Aziz · Answer

@Tapan Patel   The ouput was 13:00    So here's where user will input their time.       Here's the situation, user will input any time they want and textbox will calculate their time duration.   For example:   User insert 12:00 on the first Time Out and 13:00 on first Time In, the duration will be 1 hour or 01:00 User insert 14:00 on the second Time Out and  15:00 on second Time In, the duration will also be 1 hour or 01:00 The final duration will be between the first Time Out and the second Time In, the duration will be 3 hours or 03:00.   Problem: Insert 12:00 on the first Time Out and 12:30 on the first Time In, the duration was 30 minutes or 00:30 (This is correct) Insert 13:00 on the second Time Out and 13:30 on the second Time In, the duration was 13 hours or 13:00 (This is very wrong) The final duration was 1 hours and 30 minutes or 01:30 (This is correct)   Note: I can't find any solution of my problem here, tried suggestion from Ankit Sharma also can't show the right answer. All my dateTimePicker are set to custom format which is HH:mm. Hope you guys can really help me on this.

Tapan Patel · Answer

textBox1.Text =  new  TimeSpan(Math.Abs(dateTimePicker1.Value.Ticks- dateTimePicker2.Value.Ticks)).ToString();   If this is not working, please let me know the inputs you are putting for each datetime picker and expected value/ result for the calculation.

Shafiqq Aziz · Answer

@Tapan Patel   Nope, it return -13:00

Tapan Patel · Answer

Is this working for you? please change datepicker names as per your design.   textBox1.Text =( dateTimePicker1.Value.TimeOfDay - dateTimePicker2.Value.TimeOfDay).ToString();

Ankit Sharma · Answer

Hi Shafiqq,   Since your subtracting two timestamps, have a look at these links to get some ideas.    https://stackoverflow.com/questions/12521366/getting-time-span-between-two-times-in-c   https://stackoverflow.com/questions/9017498/calculating-how-many-minutes-there-are-between-two-times

Shafiqq Aziz · Answer

@Tapan Patel   Example:   dtpOut1 = 12:00 dtpIn1 = 12:30 dtpOut2 = 13:00 dtpIn2 = 13:00   Total duration 1 (dtpOut1 & dtpIn1) = 30 minutes Total duration 2 (dtpOut2 & dtpIn2) = 30 minutes Total duration / sum (dtpOut1 & dtpIn2) = 1 hour   Output on total duration 1 and  total duration / sum are correct. Output total duration 2 is wrong. I just create a simple math calculation like dtpIn1 - dtpOut1 = Total duration 1. Total duration 2 calculation is the same as total duration 1 but still ouput for total duration 2 is wrong.

Tapan Patel · Answer

Not sure what exactly you are trying to do here becuase you mentioned that you want total duration between dtpOut1 and dtpIn2 and that is what you have coded. Can you please give an example of input/expected output to understand the issue?