初一

first day of lunar month / New Year's Day / first year in junior middle school

at first / (at the) beginning / first / junior / basic

one / single / a (article) / as soon as / entire; whole; all; throughout / "one" radical in Chinese characters (Kangxi radical 1) / also pr. [yao1] for greater clarity when spelling out numbers digit by digit

see 躲得過初一，躲不過十五|躲得过初一，躲不过十五[duo3 de5 guo4 chu1 yi1 , duo3 bu4 guo4 shi2 wu3]

New Year's Day in the lunar calendar

lit. you may go undetected during the new moon, but at full moon you'll be found out (idiom) / fig. you can't put it off forever / sooner or later you'll have to deal with it