DayOfWeek（曜日）

Python

py

d.weekday() # カッコが必要

weekday() だけカッコ要るので注意

Swift

swift

c.component(.weekday, from: d)

PHP

rb

$d->format('w')

JavaScript

js

d.getDay()

Bash

bash

date +%u

Ruby

rb

d.wday

Excel

xlsx

=WEEKDAY()