In example 1 on the IRS website about alien residency examples the IRS arrives at the conclusion that Wei Wu's residency starting day is 01-01-2016 (he passed the substantial presence test on 07-01-2016).
I am confused as to what that means for dual status filing. I thought Wei Wu could file as a non resident alien for the year up until 07-01-2016 and as a resident alien for the rest of the year. But that doesn't make sense if his residency starting day is 01-01-2016.
What am I missing here? I am on an F-1 visa in the united states and will face this situation next year.