Data Type Date (date field: A type of field whose content is a date. Examples include the Baseline Start and Early Finish fields.)
Entry Type Entered (entered field: A field in which you may type or edit information. This is in contrast with a calculated field, in which Project calculates and enters information.)
Description The Constraint Date field shows the specific date associated with certain constraint (constraint: A restriction set on the start or finish date of a task. You can specify that a task must start on or finish no later than a particular date. Constraints can be flexible [not tied to a specific date] or inflexible [tied to a specific date].) types, such as Must Start On, Must Finish On, Start No Earlier Than, Start No Later Than, Finish No Earlier Than, and Finish No Later Than.
Best Uses Add the Constraint Date field to a task view when you want to review task constraint dates. You may find it helpful to add the Constraint Type field as well so you can see the type of constraint the date refers to.
Example You have a task that must start on a particular date, so you set a Must Start On constraint. You then specify the date (for example, November 14) that the task must start on. This constraint date is stored in the Constraint Date field.
For another task, you enter a date in the Start field. Project assigns the Start No Earlier Than constraint and uses your start date as the constraint date.
Remarks The As Soon As Possible and As Late As Possible constraints do not require dates. The Constraint Date field shows "NA" for tasks with these constraints.
If you want to indicate a deadline date without setting a constraint, you can use the Deadline field. Setting a deadline does not affect how tasks are scheduled. However, if the task's finish date is scheduled for later than the deadline date, an indicator (red diamond with an exclamation point) appears in the Indicators field. You can set a deadline with the Deadline field or on the Advanced tab in the Task Information dialog box.