# Creating a custom duration column

### Question

• Hello Sirs,

I'm creating a schedule that has variance on the baseline start & finish and actual start and finish date.

I need a column which calculates the working days difference of the actual and planned dates of both start and finish dates. At first, i thought of just a simple formula of [Actual Start]-[Baseline Start] but this considers the none working days.

Then, I thought of creating another 2 duration columns for both actual/baseline start and actual/baseline finish just to get the their working days difference but i just don't know how.

Cheers for the learning!

Newbie Planner

Sunday, August 13, 2017 2:55 AM

• Newbie Planner,

You don't need any custom fields because Project already has what you are describing. It's called the Start Variance field and Finish Variance field.

Once you set a baseline, the original plan start and finish are captured in their respective baseline fields. When you enter an actual start date, Project calculates the variance between the saved baseline date and the actual start date. The same is true for the task finish.

Note, if you update your tasks using the Percent Complete field, Project will automatically set the actual start as the scheduled start. If you enter an actual start date that is different from the scheduled start date, Project will automatically update the scheduled start to equal the actual start.

Hope this helps.

John

Sunday, August 13, 2017 1:50 PM

### All replies

• Newbie Planner,

You don't need any custom fields because Project already has what you are describing. It's called the Start Variance field and Finish Variance field.

Once you set a baseline, the original plan start and finish are captured in their respective baseline fields. When you enter an actual start date, Project calculates the variance between the saved baseline date and the actual start date. The same is true for the task finish.

Note, if you update your tasks using the Percent Complete field, Project will automatically set the actual start as the scheduled start. If you enter an actual start date that is different from the scheduled start date, Project will automatically update the scheduled start to equal the actual start.

Hope this helps.

John

Sunday, August 13, 2017 1:50 PM
• Thatz good

-sandaruwan

Sunday, August 13, 2017 2:02 PM
• Hello Sir Michael,

Thank you so much for the effort to help!

Cheers!

Newbie Planner

i'm the only one here who is the newbie planner

Tuesday, August 15, 2017 4:23 AM