比如开始月份202311,结束月份202312,天数就是30+31 =61
DATESUBDATE(MONTHDELTA(TODATE("202312","yyyyMM","zh"),1),TODATE("202311","yyyyMM","zh"),"d")
//参数的
DATESUBDATE(MONTHDELTA(TODATE($endMonth,"yyyyMM","zh"),1),TODATE($startMonth,"yyyyMM","zh"),"d")
DATEDIF(CONCATENATE(right($startMonth,4),"-",left($startMonth,2),"-01"),DATEINMONTH(CONCATENATE(right($endMonth,4),"-",left($endMonth,2),"-01"),-1),"D")