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Unable create task without start and end date and empty duration (C# .NET)

Hi, I have a trouble in creating a task. I want create task without start and end date.

        var license = new License();
        Stream licenseStream =

        var project = new Project();
        var task = project.RootTask.Children.Add("Task without dates");

        // we need have empty task without start date , end date and duration, just empty task
        task.Set(Tsk.DurationText, string.Empty);  // don't clean duration Why and how do it?
        task.Set(Tsk.FinishText, string.Empty);
        task.Set(Tsk.ActualFinish, DateTime.MinValue);

        task.Set(Tsk.ActualStart, DateTime.MinValue);
        task.Set(Tsk.StartText, string.Empty);
        project.Save("a2.XML", SaveFileFormat.XML);

But I get Task with duration 1 and not empty start and end date


I have observed your requirements and request you to please visit this documentation link to serve the purpose on your end.

Hello @LogicSoft
You can add empty task as follows

	var license = new License();
Stream licenseStream =

var project = new Project{CalculationMode = CalculationMode.Manual};
project.Set(Prj.StartDate, new DateTime(2019, 7, 30, 8, 0, 0));
project.Set(Prj.NewTasksAreManual, true);

var task = project.RootTask.Children.Add("Task without dates");
task.Set(Tsk.IsManual, true);
task.Set(Tsk.DurationFormat, TimeUnitType.Null);
task.Set(Tsk.ManualStart, DateTime.MinValue);  
task.Set(Tsk.ManualFinish, DateTime.MinValue); 
task.Set(Tsk.Duration, project.GetDuration(0)); 
task.Set(Tsk.ManualDuration, project.GetDuration(0)); 
task.Set(Tsk.RemainingDuration, project.GetDuration(8, TimeUnitType.Hour)); 
task.Set(Tsk.StartText, ""); 
task.Set(Tsk.FinishText, "");
task.Set(Tsk.DurationText, "");
project.Save("out.xml", SaveFileFormat.XML); 

Unfortunately, there is no abilito to set task duration to the empty, only to 0 day. But we will handle with it in future releases

Unfortunately, we don’t want use manual data management for setting dates. I have 2 exported files with old code and new + your advises how to set empty dates, and have different result. I expect to get same result like before.Sample Project - 1st Training (52.1 KB)


We are working on this and will share feedback soon.

BTW, what of the files you sent is correct? Please attach yout MPP file and your C# code sample and we will try to help you.

File Sample Project - 1st Training Rollout_201907311045.xml is correct was created by Aspose.Tasks 2009 for .NET
Second was created by Published by Aspose.Tasks for .NET 19.7 the same code + advices

Thank you! Can you share the code sample you are using to create the files?

Hi, Can u also share Code sample for JAVA


Can you please share which sample code you are referring to for Java.


Please use the following Java implementation for required sample code.

public static void TestTaskWithoutDate() throws Exception

    License license = new License();

    Project project = new Project();
    //Setting Calculation mode
    java.util.Calendar calTimeStart = java.util.Calendar.getInstance();
    calTimeStart.set(2019, 7, 30, 8, 0, 0);

    //Setting Minimum date
    java.util.Calendar calTimeMin = java.util.Calendar.getInstance();
    calTimeMin.setTime(new Date(0L));
    project.set(Prj.START_DATE, calTimeStart.getTime());
    project.set(Prj.NEW_TASKS_ARE_MANUAL, new NullableBool(true));

    Task task = project.getRootTask().getChildren().add("Task without dates");
    task.set(Tsk.IS_MANUAL,  new NullableBool(true));
    task.set(Tsk.DURATION_FORMAT, TimeUnitType.Null);
    task.set(Tsk.MANUAL_START, calTimeMin.getTime());  
    task.set(Tsk.MANUAL_FINISH, calTimeMin.getTime()); 
    task.set(Tsk.DURATION, project.getDuration(0)); 
    task.set(Tsk.MANUAL_DURATION, project.getDuration(0)); 
    task.set(Tsk.REMAINING_DURATION, project.getDuration(8, TimeUnitType.Hour)); 
    task.set(Tsk.START_TEXT, ""); 
    task.set(Tsk.FINISH_TEXT, "");
    task.set(Tsk.DURATION_TEXT, "");"out.xml", SaveFileFormat.XML);