Why was the Weasley family clock with an arm for each family member, showing their current whereabouts, featured in the second film when it is mentioned for the first time in the fourth Harry Potter book?
IT IS IN THE SECOND BOOK.
When Harry was saved by Ron and the twins from the Dursleys, and went to the Burrow afterwards. This is Harry's first time in The Burrow, though.
The clock on the wall opposite him had only one hand and no numbers at all. Written around the edge were things like Time to make tea, Time to feed the chickens, and You’re late.
Harry Potter and the Chamber of Secrets, Chapter 3, The Burrow