WordPress at a glance
function is not described

WP_Query::is_day() WP 3.1.0

Is the query for an existing day archive?

This is a method of the class: WP_Query

No Hooks.

Return

true/false.

Usage

$WP_Query = new WP_Query();
$var = $WP_Query->is_day();

Changelog

Since 3.1.0 Introduced.

Code of WP Query::is day: wp-includes/class-wp-query.php WP 5.2.2

<?php
public function is_day() {
	return (bool) $this->is_day;
}