Based on the provided information, "Per vandaag behoort het niet mij of een ander toe" (3+1 letters), the answer could be:
Vandaag (6 letters)
The word "Vandaag" means "today" in Dutch. It implies that something does not belong to anyone today, suggesting a change in ownership or status that has recently occurred.
Since the answer requires 4 letters, a possible alternative could be:
Niemands (7 letters)
This word means "no one's" or "belonging to nobody" in Dutch. It directly conveys the idea that something does not have an owner, aligning with the provided phrase.
However, if the answer must strictly be 3 letters, there might not be a single word that perfectly fits the given description.
Please let me know if you have any other questions or require further assistance.