inset day
noun [ C ] education UK specialized uk/ˈɪn.set ˌdeɪ/ us/ˈɪn.set ˌdeɪ/ (also teacher training day)
（英国中小学教师的）在职培训日（inservice training day 的简略说法，教师到校参加培训或其他校务活动，学生不到校）
short for inservice training day: in the UK, a day when teachers go into school without any students present, in order to do training, planning, etc.
My two children attend two different state schools, with different holidays, inset days and so on. 我的两个孩子在两所不同的国立学校上学，假期、教师培训日等都不同。
The impact of secondary school curriculum changes are too great to be decided in just one inset day. 中学课程改革影响巨大，不可能在培训日这样短短的一天内决定。
- More examples
- Inset days should be used for in-service training.
- Some parents do question whether inset days are a good reason to interrupt their child's education.
- Countless inset days and training evenings helped to "redefine expectations".