lunch hour       
noun [ C ] uk/ˈlʌntʃ ˌaʊər/ us/ˈlʌntʃ ˌaʊr/ (also lunch break)
 午餐时间,午休时间
the period in the middle of the day when people stop work to have lunch
  I did it during my lunch hour. 我在午餐时间做了此事。 
UK also I did it in my lunch hour. 我在午餐时间做了此事。