Which DOW number maps to Sunday?

Question

Accepted Answer

In PostgreSQL, EXTRACT(DOW FROM date) returns the day of week as an integer from 0 (Sunday) through 6 (Saturday). So Sunday is 0, not 7. EXTRACT(DAY FROM ...) gives the day of the month (1-31), not the day of the week. MySQL uses DAYOFWEEK() where 1=Sunday, making the numbering off-by-one compared to PostgreSQL - always check the documentation for the database you are using.