Excel has a feature that when you fill in a date, it can automatically give you the day of the week. This is nice when looking at ancesters birthdates, as wellas other important dates.
Hello,
This is simply how you format the cell data. Right click the cell, choose Format cells.... In Category choose Date. Then in the Format section select one with you preference of how you want the day displayed - ie: Friday, December 31, 1999.
The N’s in the format code determine how & where the day is displayed. NN is abbreviated day and NNN is full day name.
Same with DDD and DDDD
I want to get the day of the week, from a date value in a different column, without a long list of “IF” statements.
You had been given the answer ~3 years ago 
Anyway - asking a question as an “answer” to another question is incorrect.