I was going to use annual leave in December for personal reasons, but the company didn’t approve my annual leave application because it is busy at year-end. If the company does not approve my annual leave but I do not go to work, can the company consider me absent without approval and take disciplinary action? If an employer does not approve maternity or childcare leave, not annual leave, and the worker does not go to work anyways, does this amount to unauthorized absence?

In principle, an employer should grant annual paid leave for the dates an employee requests it. In other words, the period for annual paid leave should be decided by employees, not by the company, and used freely. However, if the employee taking leave on the relevant dates could reasonably result in serious business problems, it is possible for the employer to give leave on dates the employee did not request. Whether or not granting leave on the requested dates would result in serious business problems will be judged in consideration of circumstances such as the size of the company, the position of the annual leave applicant, the details and nature of his/her work, difficulty of arranging a replacement during the requested period, and the number of workers applying for annual leave for the same period. Since the exact situation is unknown, an exact answer cannot be given here. However, when considering all circumstances, if there is no serious obstacle to the operation of business, the days used for vacation cannot be treated as an unauthorized absence.
On the other hand, maternity leave and childcare leave are compulsory provisions when certain criteria are met. Employers must give childcare leave when an application is filed. Maternity leave must be given even without application once the employer learns the worker has given birth. The employer does not have a right to change the maternity or childcare leave period, unlike with annual paid leave. So, if the employer does not approve the leave application without justifiable reason and an applicant starts his/her leave or vacation anyways, it cannot be seen as unauthorized absence on the part of the worker.