DOW is 0-based? - Mailing list pgsql-general

Is there a rational reason why Day of the Week is 0-based, i.e. Sunday (0) to Saturday (6) instead of the more intuitive Sunday (1) to Saturday (7)?

    SELECT date_part('dow', current_date);

https://www.postgresql.org/docs/current/static/functions-datetime.html

Thanks,