How to automatically fill, sort and conditionally format 1st day of the week according to given year and month

Question

How can I fill-in column A, make it start with the day's name according to the year in A2 and month in A1 and conditionally format them?

https://docs.google.com/spreadsheets/d/1Dvi7FKZwz14Taivt5fJNqDxcQGFJb1jrS5kqJdbzYXw/edit?usp=sharing

Answer 1

Please use the following formula

=SEQUENCE(COUNT(B5:B),1,DATE(A2,MONTH(A1&1),1),1)

You then format your cells as Tue found under Format >Number >More date and time formats

I also noticed that you have the following conditional formatting applied, which will no longer work

=OR($A5="Fri",$A5="Sat")

What you should now use is

=OR(WEEKDAY($A5)=6,WEEKDAY($A5)=7)