“清除历史记录”维护计划任务能够将此选项设置为以小时为单位删除文件。

The History Cleanup maintenance plan task includes the ability to set the option to delete files using a unit in hours.

youdao

管理下载历史：不需要保留下载记录，所以我建议设置当火狐退出时清除下载管理器里的文件。

Download Manager History: There's no need to keep track of all of your downloads, so I suggest setting it to Remove Files From The download Manager When Firefox Exits.

youdao