Understanding Task Start & Due Date Behavior in Outlook


A common process when managing Tasks in Outlook is to set the Start Dates & Due Dates, and change these dates when needed.  The logic in Outlook does not allow you to set a Due Date to a date before the Start Date or set the Start Date to a date after the Due Date.  This blog post will describe the results you can expect for various scenarios when you change the Start and Due Dates of a Task.

 

Scenario #1. You change the Due Date of a task before the Start Date.

Result:

Outlook for Mac 2011 & Outlook 2016 for Mac – The Start Date is automatically moved to be the same as the Due Date.
Outlook 2010 & 2013 – You receive an error “The due date of a task cannot occur before its start date.”

Examples:

Windows Outlook 2013 or 2010:

The Tasks Start Date is April 1 and the Due Date is April 5. 
You try to change the Due Date to March 30.
You receive this error message.


Outlook 2016 for Mac or Outlook for Mac 2011:

The Tasks Start Date is April 1 and the Due Date is April 5. 
You change the Due Date to March 30. The Start Date changes to March 30 automatically.

 

 

Scenario #2: You change the Start Date of a Task that also has a Due Date set.

Result:

All Outlook versions: The Due Date automatically changes preserving the duration of the task.

Example:

You have a task that starts on April 1 and is due on April 5. 
You then change the start date to April 3, and the Due Date automatically changes to April 7.

Scenario #3: The Start Date of a task is initially set to None with a Due Date set, and then you set the Start Date to a date later than the Due Date.

Result:

All versions of Outlook: The Due Date will change to the same date as the new Start Date that was set.

Example:

The Task Start Date is set to None, and the Due Date is set to April 5.
You set the Start Date to April 10
The Due Date is automatically changed to April 10.

Comments (1)

  1. Thank you for explaining it to us.
    Please keep this blog post updated with new post.

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