30是第十周 你可以替换成变量
dateInWeek(DATEDELTA(TODAY(),-(WEEK(TODAY())-30)*7),-1) 最后一天
dateInWeek(DATEDELTA(TODAY(),-(WEEK(TODAY())-30)*7),1) 第一天
==========
NF为年份,WK为当前周
dateInWeek(DATEDELTA(format($NF+"-02-01","yyyy-MM-dd"),-(WEEK(format($NF+"-02-01","yyyy-MM-dd"))-$WK)*7),-1) 最后一天
dateInWeek(DATEDELTA(format($NF+"-02-01","yyyy-MM-dd"),-(WEEK(format($NF+"-02-01","yyyy-MM-dd"))-$WK)*7),1) 第一天