You must apply for parental leave at least seven weeks before it begins. For mothers on maternity leave, this means that they must submit their application for parental leave to their employer within one week of the birth. If fathers want to take parental leave immediately after the birth of their child, they should base their application on the expected date of birth.
As a rule, you should generally speak to your employer in advance; they are often flexible in adjusting your parental leave, even if the actual date of birth does not correspond to the calculated date. In urgent cases, such as the premature birth of a child, shorter deadlines apply for an application for parental leave. In this case, you should simply apply for parental leave as soon as possible.