It is a default specification.
If there is no schedule pattern, and some kind of attendance data such as the remarks column or the type of work day is entered, some schedule is always assigned.
Therefore, first, the schedule pattern registered in auto schedule setting (or auto schedule setting for each employee) is registered.
If no auto schedule setting (or auto schedule setting for each employee) is registered, an empty schedule with the name "--" is assigned.
An empty schedule named "Shift (-)" is assigned to input work start/end time limits and break start/end times.