A late innovation of the Aristocratic understanding of
בין חערבים (byn ha-arabim) arose sometime after the fall of Jerusalem in 70 C.E., becoming clearly manifested in records by the 8th century C.E.
This new interpretation (System C) was built under the heavy influence of the Talmudists (spiritual offshoots of the Pharisees). It flourished primarily among the Karaites and neo (later)-Samaritans but was also practiced by some less well-known groups.
Like those of the Aristocratic school (System A), these neo (later)-Aristocratic groups (System C) understood byn ha-arabim as the period of twilight that follows sunset.