A dad in the UK who took his daughter to Disney World during school time has been told he did break the law.
The Supreme Court in the UK has ruled that he acted unlawfully.
Jon Platt refused to pay a €140 fine to the Isle of Wight Council over the unauthorised trip to Florida.
He had argued in court it was OK, because legislation states attendance must only be "regular".
But Supreme Court judges said any kind of truancy is unfair on others.
The Council appealed against an earlier court judgment that said Platt had no case to answer.
This case has implications for any parent in the UK who takes their child on holiday during term time without permission from the headteacher.