Reply To: Chidushim on Daf Yomi Shabbos 30

שבת לד,א

The three things mentioned in the mishna is said Yom Kippur Kol Nidrei Night to emphasize the fear of the day. עשרתם, the ten days of teshuva passed, we should have done teshuva, ערבתם, Erev Yom Kippur passed and הדליקו את הנר how frightening it is after the candles have been lit for Yom Kippur.
ספק חשיכה ספק אינה חשיכה its obvious if not one than the other? Answers the Tosfas Chadoshim on the Mishnayos a beautiful answer. The first part applies to Erev Shabbos as maybe it is already night, already shabbos and the second part applies to motzei shabbos as maybe it is not night yet, still shabbos.