二十日正月
はつかしょうがつ
twentieth day of the first month (end of New Year celebrations, upon which remaining New Year's food is eaten, decorations are stowed away, etc.)
二月病 is read as にがつびょう (nigatsubyou) and means blues experienced by man who did not receive Valentine's day chocolate.
にがつびょう
nigatsubyou
はつかしょうがつ
twentieth day of the first month (end of New Year celebrations, upon which remaining New Year's food is eaten, decorations are stowed away, etc.)
しがつびょう
euphoria experienced by college students or workplace recruits at the beginning of school or work
ごがつびょう
blues experienced by college freshmen or workplace recruits shortly after beginning school or work