Haneitz is generally considered the beginning of the day
The Neitz is
never considered the beginning of the day.
All mitzvos that are required to be done by day, one is yotzei if done after the alos.
Most are required lchatchilah to wait for the neitz to assure it is actually after the alos...
If neitz was considered the beginning of the day it would mean you are yotzei shachris megillah and daled minim if done by night.....