EstR[2] 12.2(25) :חדא לז׳ יומין‏ :
See the entire entry for z sym. 7th letter of alphabet

EstR[2] 12.2(25) :בניסן פסחא‏ : Passover is in Nisan
See the entire entry for nīsān n.m. Nisan (March/April)