Due dates can now be added to workflow steps so that they can have deadlines and be more easily reported on. This can be done in both a record type's workflow settings as well as on individual pre-existing records. On pre-existing records, users with "Can Edit" or higher access can manually set and edit Due Dates.
In a record type's workflow settings, you can set a programmatic Due Date on any step for:
X Days after step assignment
X Days after step activation
X Days after record submission
You can elect to have a step auto-complete on its Due Date. Also, you can set reminder notifications for X days before or after a Due Date to any user in the system: