promql/functions.go
func funcDayOfWeek(vals []Value, args Expressions, enh *EvalNodeHelper) Vector {
	return dateWrapper(vals, enh, func(t time.Time) float64 {
		return float64(t.Weekday())
	})
}
func funcDayOfWeek(vals []Value, args Expressions, enh *EvalNodeHelper) Vector {
	return dateWrapper(vals, enh, func(t time.Time) float64 {
		return float64(t.Weekday())
	})
}
// === day_of_week(v Vector) Scalar ===