You can take paid holidays as soon as you earn them. In principle, the days you earn in one month can be used for paid holidays as early as the following month. However, taking time off requires an agreement with your employer. Many employers prefer holidays to be taken in full weeks, but workplace norms for this can vary.
Fifteen of the paid holiday days you earn must generally be reserved for consecutive time off during the period from May 1st to September 30th.
Contact your local 3F branch or contact your trade union representative if you have any further questions concerning your holiday entitlement.