Language reference
ISODOW (ISO day of week, Monday 1)
Syntax
ISODOW(<date-or-timestamp>)
σ ISODOW(order_date) ≤ 5 (Orders)Description
ISODOW gives the day of the week as ISO 8601 numbers it, Monday 1 through Sunday 7. Use it where the week starts on Monday, as it does in most of the world.
Technical Description
ISODOW(d) → NUMBER, 1 (Monday) to 7 (Sunday). It is EXTRACT(ISODOW FROM d). Accepts a DATE or TIMESTAMP (a TIMESTAMP is read at UTC); other types are an evaluation error. NULL input returns NULL. PURE, DETERMINISTIC.
Examples
Weekdays only:
σ ISODOW(order_date) ≤ 5 (Orders)SELECT ISODOW(order_date) <= 5 (Orders)Pushdown
SQL: EXTRACT(ISODOW FROM <col>) on PostgreSQL and DuckDB, WEEKDAY(<col>) + 1 on MySQL; in the engine elsewhere. MongoDB: $isoDayOfWeek.
Limitations
The same day as DOW except that Sunday is 7 rather than 0.