How do you expect MS Project (MSP) to behave when you enter an Actual Start date for a task? You would likely expect it to store the date in the ‘Actual Start’ field and stop there, but MSP does something more than that. MSP also changes the ‘Start’ date field if the Actual Start is different from the Planned Start.

Let us do a small exercise to illustrate the best practices for dealing with dates in MSP.

1. Open MSP and insert columns for Actual Start and Actual Finish in the Gantt chart view. Refer to figures I and II below.

Figure I


Figure II


2. Enter a new task. MSP treats Start and Finish dates as the planned dates. It uses the Project Start date as a default date for these fields. It will put ‘NA’ by default in Actual date fields. See figure III below.

Figure III


3. Now put a number in the Duration field. You will notice that the Finish date is automatically calculated, but that nothing changes in the Actual dates. Refer to figure IV below.

Figure IV


4. Enter an Actual Start date that is different from the Start date. You will notice that the Start date, too, changes to Actual Start date and a new Finish date is calculated. Refer to figure V below.

Figure V


The Conundrum of Actual Dates

Let me give you an explanation for why Actual dates change planned dates by walking you through another exercise. You can also read this article for more information.

1. Add a second task in MSP, and put a number in the Duration field. Refer to figure VI below.

Figure VI


2. Put a Finish to Start relationship between the first and the second task. Refer to figure VII below.

Figure VII


3. Enter an Actual Finish date for the first task that is different from the Finish date. You will notice that the Finish date, too, changes to the Actual Finish date. Refer to figure VIII below.

Figure VIII


Now this seems to be completely logical. The second task is dependent on the first, so it can start only after the first task is finished. MSP recognizes this and automatically changes the planned Start date of the second task.

MSP treats ‘Start’ and ‘Finish’ dates as pertaining to the current schedule. It maintains the schedule by automatically changing them if the dates of a Predecessor task changes.  However, this creates another problem. What if we wanted to see the original plan date and wanted to track a project’s actual progress against it? We use Baseline dates.


Baseline Dates

MSP has a third set of dates, which are used to store the original plan. These are called Baseline dates, and they help in tracking and in the reporting of a project.

Let us do a third exercise, which I hope will shed some light on how to use Baseline dates.

1. Create a new project in MSP and insert four columns in the Gantt chart view:

    1. Actual Start
    2. Actual Finish
    3. Baseline Start
    4. Baseline Finish

Refer to figure IX below.

Figure IX


2. Enter two new tasks and make the second task dependent on the first. MSP will put ‘NA’ by default in the Actual and Baseline date fields. Refer to figure X below.

Figure X


3. Put a number in the Duration field of both the tasks. Finish dates for these tasks will automatically change. Refer to figure XI.

Figure XI


4. Set Baseline dates. The baseline dates are automatically set to Start and Finish dates respectively, but Actual dates will remain ‘NA.’ Refer to figures XII and XIII below.

Figure XII


Figure XIII


5. Enter the Actual Start date for the first task (a different date than the Start date). You will notice that the Start date will change to Actual Start date, but that the Baseline Start will remain same.

Figure XIV


Baseline dates store the original set of planned dates. They can be used to track the project progress.


MSP Best Practices

My recommended best practices for dealing with dates in MSP are listed below:

  • Always define a predecessor task when entering a new task. You can do this for all your tasks except for the first one. This way MSP will automatically calculate Start and Finish dates of successors.
  • Avoid assigning resources to summary tasks.
  • Avoid linking summary activities.
  • Always use set Baseline dates after creating the initial schedule. This way you will be able to track the project progress against the original schedule.
  • Take care of task types while creating and tracking project tasks.
  • You can use a combination of entering Actual dates directly in the Gantt chart view or use percentage finish option.



MSP has three sets of dates. All of them have their own purpose. Baseline dates store the original schedule, Start/Finish dates store the current schedule, and Actual dates are used to track the ongoing and finished tasks.

Did you know MSP has nine other set of Baseline, Planned, and Actual dates? Have you used them? Which set of dates to you work with most often? I would love to hear your thoughts in the comments below.