wp_checkdate()

wp_checkdate( int $month, int $day, int $year, string $source_date ): bool

function wp_checkdate( $month, $day, $year, $source_date ) {
	$checkdate = false;
	if ( is_numeric( $month ) && is_numeric( $day ) && is_numeric( $year ) ) {
		$checkdate = checkdate( (int) $month, (int) $day, (int) $year );
	}

	/**
	 * Filters whether the given date is valid for the Gregorian calendar.
	 *
	 * @since 3.5.0
	 *
	 * @param bool   $checkdate   Whether the given date is valid.
	 * @param string $source_date Date to check.
	 */
	return apply_filters( 'wp_checkdate', $checkdate, $source_date );
}