Unexcused absence is a serious breach of duties even with prior notice; self-granted leave does not excuse absence.

The Supreme Court dismissed the cassation appeal against a disciplinary fine imposed for unexcused absence. The employee failed to provide medical documentation for his illness and attempted to use accrued overtime hours as a substitute for leave, which the employer refused. The court ruled that only the employer can grant time off for overtime and that self-declared leave does not justify absence without official proof.