丁是丁，卯是卯 (dīng shì dīng,mǎo shì mǎo)

1. 丁、卯分別是天干、地支之一,不能相混,錯亂了影響記時。形容做事認真,一絲不茍 be conscientious and meticulous;be accurate in what one says;be fastidiously accurate
   • 鳳姐笑道:“我看你厲害,明兒有了事,我也是丁是丁,卯是卯的,你也別抱怨?！?a href="/hycd/h/h247666.htm" target="_blank">紅樓夢》
2. 也作“釘是釘,鉚是鉚”