Polish Labour Code (Art. 153 and 154: The length of annual leave)
The first annual leave: In the calendar year in which an employee takes up work for the first time, he acquires the right to leave after each month of work amounting to 1/12 of the leave he is entitled to after one year of work. Subsequent leave: An employee acquires the right to subsequent leave in each successive calendar year. The length of leave amounts to: 1) 20 days – if an employee has been employed for fewer than 10 years, 2) 26 days – if an employee has been employed for at least 10 years. The length of leave for a part-time employee is proportionate to the working time of this employee, taking the length of leave determined above as a basis; a part of a day of leave shall be rounded up to a full day.