Hi Purnima,
We are sorry for the inconvenience caused to you.
You may please use cal.GetWorkingHours() such that complete start/finish date and time is mentioned. If you set finish date like 2016,12,31, it will be taken as 2016,12,31 00:00:00 and hence the day 31st will not be taken into account.
Following sample code is tested for different dates and working fine.
<span style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre; background-color: rgb(255, 255, 255);”>Project proj = <span class=“kwrd” style=“color: rgb(0, 0, 255); font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre;”>new<span style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre; background-color: rgb(255, 255, 255);”> Project(@“Blank2010.mpp”);<br style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre;”><span style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre; background-color: rgb(255, 255, 255);”>Task task1 = proj.RootTask.Children.Add(“Task 1”);<br style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre;”><span style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre; background-color: rgb(255, 255, 255);”>task1.Set(Tsk.IsManual, <span class=“kwrd” style=“color: rgb(0, 0, 255); font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre;”>true<span style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre; background-color: rgb(255, 255, 255);”>);<br style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre;”><span style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre; background-color: rgb(255, 255, 255);”>DateTime startDate = <span class=“kwrd” style=“color: rgb(0, 0, 255); font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre;”>new<span style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre; background-color: rgb(255, 255, 255);”> DateTime(2016, 8, 3,8,0,0);<br style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre;”><span style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre; background-color: rgb(255, 255, 255);”>DateTime finishDate = <span class=“kwrd” style=“color: rgb(0, 0, 255); font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre;”>new<span style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre; background-color: rgb(255, 255, 255);”> DateTime(2016, 8, 31,17,0,0);<br style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre;”><span style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre; background-color: rgb(255, 255, 255);”>task1.Set(Tsk.Start, startDate);<br style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre;”><span style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre; background-color: rgb(255, 255, 255);”>ATasks.Calendar cal = proj.Get(Prj.Calendar);<br style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre;”><span class=“kwrd” style=“color: rgb(0, 0, 255); font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre;”>double<span style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre; background-color: rgb(255, 255, 255);”> totalHours = cal.GetWorkingHours(startDate, finishDate).WorkingHours.TotalHours;<br style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre;”><span style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre; background-color: rgb(255, 255, 255);”>task1.Set(Tsk.Duration, proj.GetDuration(totalHours, TimeUnitType.Hour));<br style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre;”><span style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre; background-color: rgb(255, 255, 255);”>proj.Save(“output2.mpp”, SaveFileFormat.MPP);<br style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre;”><span style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre; background-color: rgb(255, 255, 255);”>
<br style=“font-family: “Courier New”, Consolas, Courier, monospace; font-size: small; white-space: pre;”>
I have also tried task.Set(Tsk.IsManual, true) and found it working fine. Could you please share the feedback again after testing above code?