We have noe looked at how to manually do shift planning by using the Work planner interface to work with the profile calendar table. If you want to automate the shift process, you can do so as well. The profile group can be associated with a setup that automatically assign a profile based on the clock in time.
Go to your Profile groups (Time and attendance > Setup > Time profile > Profile group)
and click the Profile relation menu item.
Add your profile and the time intervals that the clock in time should trigger at.
You can also create regular shift variations. Like for instance in high demand season (01.03..31.08) we run three shift, but in low season we run only two.