Designation of days and hours in terms of the heavenly stems and earthly branches is held as an important basis for point selection according to the ancient acupuncture theory of Ziwu Liuzhu (midnight-moon ebb flow). While the heavenly stems and earthly branches are predicted on the base of particular times. Therefore, what standard of time should be adopted is essential for acupuncture based on Ziwu Liuzhu. The article has pointed out the possible errors in adopting Beijing time, local mean solar time and real solar time. It proposes that real solar time should be adopted as the time standard for acupuncture based on Ziwu Liuzhu in the view of analysis of the theory itself and history background of the generation of the theory. It is also suggested to explore a particular software or establish a website for assistance of the acupoint selection.