https://support.us.edu/hc/en-us/community/posts/26995515261591–%EF%BC%A6%EF%BC%A1%EF%BD%91-KLM-What-is-the-24-hour-rule-for-KLM

https://support.us.edu/hc/en-us/community/posts/26995515261591--%EF%BC%A6%EF%BC%A1%EF%BD%91-KLM-What-is-the-24-hour-rule-for-KLM