Sunday.
Why?
The day before the day before yesterday was Monday
implies that today is Thursday.
This is true because the 'day before yesterday (Wednesday)' would be Tuesday, and the day before Tuesday is Monday.
Since today is Thursday, that means that the "day after tomorrow(Friday)" is Saturday, and the day after that is Sunday.
***
uh, that is incorrect.
if TODAY is WEDNESDAY, then YESTERDAY would be TUESDAY, and the DAY BEFORE that would be MONDAY.
now that we've established that TODAY is WEDNESDAY, then TOMORROW would be THURSDAY, and the DAY AFTER would be FRIDAY. so the ANSWER IS FRIDAY.
***
never mind. misread the question.
Friday
If 4 days after the day before yesterday is Sunday tomorrow is... 7-4+2+1 = 6 (Saturday) Forget the first part. Tomorrow is Tuesday. Great question.
4 days after Sunday is Thursday and this is the day before yesterday. Yesterday would mean you have to advance one day, the day b/f yesterday means you have to advance two days. So the day is Thursday + 2 days or Saturday.
Many options: Yesterday, Today and Tomorrow, or Today, Tomorrow and the Day after Tomorrow, or name them in a language other than English.
If it answers the question "when" for an action verb ("I will leave tomorrow"), it is an adverb. It can also be a noun ("Tomorrow is another day").
Monday. If yesterday was Friday, then today is Saturday and the day after tomorrow is Monday.
Monday
Tuesday
Let Yesterday=-1 Today=0 Tomorrow=1 the day after yesterday=(-1)+1=0=Today the day before the day after yesterday=(-1)+[(-1)+1]=(-1)=Yesterday !!! Answer = Yesterday
Today would be Monday
Friday
Friday. The day before yesterday (WED) was two days after Monday.
Monday
Five days after Wednesday is Monday. So if Monday is the day after tomorrow, today is Saturday.
yesterday
Tomorrow.
If 5 days before the day after tomorrow was Wednesday, then the day after tomorrow is Friday. Therefore, yesterday was Thursday.