Personal opinion: Teachers' vacation should be no different from other vacations, except family affairs, physical discomfort and so on. You can elaborate on it. For example, what did you do some time ago? It can be said that some changes need to be dealt with in time, or something needs to be done afterwards, and now something needs to be prepared. However, if you want to ask for leave, you'd better explain the situation directly to the leader. As long as it is reasonable, it will generally not disagree. Thank you.