Calculating the week number of a year in Excel

Question

I'm trying to calculate the week number of a week in a year in excel using the formula =WEEKNUM(A1,2).

My Result:

----------------------
|  Date    |   Week  |
|2021-01-01|    1    |
|2021-01-02|    1    |
|2021-01-03|    1    |
|2021-01-04|    1    |
|2021-01-05|    1    |
|2021-01-06|    1    |
|2021-01-07|    1    |
----------------------

The result which I want:

----------------------
|  Date    |   Week  |
|2021-01-01|    53   |
|2021-01-02|    53   |
|2021-01-03|    53   |
|2021-01-04|    1    |
|2021-01-05|    1    |
|2021-01-06|    1    |
|2021-01-07|    1    |
----------------------

Since Date 1,2,3 are in the last week of the last year.

How do I get the above result?

Answer 1

Here is my excel formula.

=IF(AND(A1>=DATE(YEAR(A1),1,1),A1<DATE(YEAR(A1),1,8)-WEEKDAY(DATE(YEAR(A1),1,6))),53,WEEKNUM(A1,2))