The Constraint date data type is one of two data types used to configure constraints in Gantt views.
The Constraint date data type is set to Strict by default and cannot be changed. From the Update column dialog, you can opt for the Constraint date column to contain Date or Date and time values, as well as configure the date format and location.
The Constraint date data type can only be applied at the column level and can only be applied in worksheets with Project Management enabled.
Learn more about constraint types and how they’re used in project management, or learn about configuring constraints in Gantt views.