TAD B3.11 R.1 :ב20 לאדר הו יום 8 לכיחך שנת 3 ארתחשסש מלכא‏ : on the 20th of Adar, which is the 8th day of Choiak, third year of King Artaxerxes
See the entire entry for kyḥk n.m. Choiak (Egyptian month = March/April)