The Parent Trap (1998)

Plot hole: The parents meet and get married on the QE II and then we jump to 11 years and nine months later, which is the time the girls get to camp. It comes out that they will both celebrate their 12th birthdays on October 11, so at the time of the camp (which must be around July/August) they are 11 years and around 9 months. So either they were born almost immediately after conception or the timeframe is off.

Plot hole: Hallie and her father would not have been able to get to Annie and her mother's house before they did, even if they did take the Concorde.