Kernrechtsfrage
Whether the employee proved an earlier start date of 2017-08-28 instead of 2017-09-18.
Extrahierter Entscheid
No. The employee did not prove an earlier commencement date; the written contract date controlled.
Extrahierte Begründung
In simplified proceedings the court investigates ex officio, but the burden of proof remains with the party asserting the fact. The appellant's statements were inconsistent and insufficient to establish an earlier start.