They can also be assigned to each job task in the Job Schedule window. Both are accessed through the job schedule window's tool bar buttons. Automatic scheduling is used to create a ballpark schedule when the job is initially opened. Rescheduling tasks rearranges an existing job schedule when the job needs to be either postponed or rushed or when you open a new job by cloning an existing one. Then, you don't have to adjust each task individually.
Automatic scheduling is used when a job is brand new, before it's been scheduled.
These lead times are set up in the Task Table, then copied to new jobs automatically, but can be edited in the job's schedule window. The Automatic option starts with either the job's start date or due date, then looks at each task. Once the ballpark schedule is created, its dates and other information should be fine-tuned. Use the Reschedule Tasks option to update a job's schedule when the job is either delayed or accelerated or when you open a new job by cloning an existing one. Then, you don't have to adjust each task individually.