驴年马月lǘ nián mǎ yuè指不可知的年月(就事情遥遥无期,不能实现说){year of the donkey and month of the horse — time that will never come (as there is no such year or month in the Chinese calendar)}: 照你这么磨磨蹭蹭,～也干不成。{If you go on dawdling like this, you will achieve nothing no matter how long you do it.}也说also猴年马月{hóu nián mǎ yuè}。