如何查找两个月未访问的文件列表?

I am creating a app which is used to download files from internet and saves into document directory.At one time that document directory occupied huge memory because user has saved more files.Now I decide to delete the files which are not accessed by user for last two months.I want to know Is there any in build Ios options to find list of files under document directory based on files modification date?please help me.I am creating a app which is used to download f