Working days between two dates in Snowflake

Here's an article with a calendar table solution that also includes a UDF to solve this in Snowflake (the business days are hard-coded, so that does require some maintenance, but you don't have to maintain a calendar table at least):

https://medium.com/dandy-engineering-blog/how-to-calculate-the-number-of-working-hours-between-two-timestamps-in-sql-b5696de66e51

After doing research work on snowflake datediff function, I have found the following conclusions.

1. DATEDIFF(DAY/WEEK, START_DATE, END_DATE) will calculate difference, but the last date will be considered as END_DATE -1.
2. DATEDIFF(WEEK, START_DATE, END_DATE) will count number of Sundays between two dates.

By summarizing these two points, I have implemented the logic below.

SELECT 
    ( DATEDIFF(DAY, START_DATE, DATEADD(DAY, 1, END_DATE))
    - DATEDIFF(WEEK, START_DATE, DATEADD(DAY, 1, END_DATE))*2 
    - (CASE WHEN DAYNAME(START_DATE) != 'Sun' THEN 1 ELSE 0 END)
    + (CASE WHEN DAYNAME(END_DATE) != 'Sat' THEN 1 ELSE 0 END)
    ) AS WORKING_DAYS