Hospitality rosters rarely fit a nine-to-five model. A split shift covering lunch and dinner is two blocks in one day, and the hours worked have to reconcile to payroll without anyone retyping them.
Vestibel models a shift as a template with one or more segments, and a working day as a single attendance record carrying one or more punches. A split shift produces two punches on one record, not two records — which is what keeps day counts, off-day entitlements and overtime honest.
Payroll lines generate from that attendance data and can be regenerated safely: any line a manager has locked survives every regeneration untouched.