He made the statement on a Sunday. Yesterday is tomorrow only on the day before yesterday. So if the day before yesterday is Friday then the day that he made that statement is Sunday.
Answer: He made the statement on Sunday.
Wednesday
There is two way to interpret this. A) If z + 1 ==> z - 1 Then z ==> z - 2 z - 2 = Friday z = Sunday
B)If z - 1 ==> z + 1 Then z ==> z + 2 z + 2 = Friday z = Wednesday
Option B) makes sense and hence the answer.
Tomorrow is neither Wednesday nor Thursday.
Yesterday was not Friday or Saturday.
Today is not Thursday or Sunday or Monday.
What day is it today?
When the day after tomorrow is yesterday, today will be as far from Wednesday as today was from Wednesday when the day before yesterday was tomorrow. What is tomorrow?