golden hour

/var/www/html/wp-includes/blocks

File/Folder	Size	Actions
archives	-
archives.php	2.7 KB
audio	-
block	-
block.php	1.47 KB
button	-
buttons	-
calendar	-
calendar.php	1.53 KB
categories	-
categories.php	2.59 KB
code	-
column	-
columns	-
cover	-
embed	-
file	-
file.php	897 B
freeform	-
gallery	-
group	-
heading	-
html	-
image	-
index.php	2.54 KB
latest-comments	-
latest-comments.php	4.88 KB
latest-posts	-
latest-posts.php	6.96 KB
legacy-widget	-
legacy-widget.php	3.73 KB
list	-
loginout	-
loginout.php	1.35 KB
media-text	-
missing	-
more	-
nextpage	-
page-list	-
page-list.php	7.09 KB
paragraph	-
post-content	-
post-content.php	1.84 KB
post-date	-
post-date.php	1.5 KB
post-excerpt	-
post-excerpt.php	2.38 KB
post-featured-image	-
post-featured-image.php	1.31 KB
post-template	-
post-template.php	2.66 KB
post-terms	-
post-terms.php	1.63 KB
post-title	-
post-title.php	1.57 KB
preformatted	-
pullquote	-
query	-
query-pagination	-
query-pagination-next	-
query-pagination-next.php	2.45 KB
query-pagination-numbers	-
query-pagination-numbers.php	2.72 KB
query-pagination-previous	-
query-pagination-previous.php	1.99 KB
query-pagination.php	359 B
query-title	-
query-title.php	1.35 KB
query.php	304 B
quote	-
rss	-
rss.php	3.21 KB
search	-
search.php	6.57 KB
separator	-
shortcode	-
shortcode.php	697 B
site-logo	-
site-logo.php	4.84 KB
site-tagline	-
site-tagline.php	994 B
site-title	-
site-title.php	1.21 KB
social-link	-
social-link.php	57.92 KB
social-links	-
spacer	-
table	-
tag-cloud	-
tag-cloud.php	1.24 KB
text-columns	-
verse	-
video	-

Edit: calendar.php

<?php
/**
 * Server-side rendering of the `core/calendar` block.
 *
 * @package WordPress
 */

/**
 * Renders the `core/calendar` block on server.
 *
 * @param array $attributes The block attributes.
 *
 * @return string Returns the block content.
 */
function render_block_core_calendar( $attributes ) {
	global $monthnum, $year;

$previous_monthnum = $monthnum;
	$previous_year     = $year;

if ( isset( $attributes['month'] ) && isset( $attributes['year'] ) ) {
		$permalink_structure = get_option( 'permalink_structure' );
		if (
			strpos( $permalink_structure, '%monthnum%' ) !== false &&
			strpos( $permalink_structure, '%year%' ) !== false
		) {
			// phpcs:ignore WordPress.WP.GlobalVariablesOverride.OverrideProhibited
			$monthnum = $attributes['month'];
			// phpcs:ignore WordPress.WP.GlobalVariablesOverride.OverrideProhibited
			$year = $attributes['year'];
		}
	}

$wrapper_attributes = get_block_wrapper_attributes();
	$output             = sprintf(
		'<div %1$s>%2$s</div>',
		$wrapper_attributes,
		get_calendar( true, false )
	);

// phpcs:ignore WordPress.WP.GlobalVariablesOverride.OverrideProhibited
	$monthnum = $previous_monthnum;
	// phpcs:ignore WordPress.WP.GlobalVariablesOverride.OverrideProhibited
	$year = $previous_year;

return $output;
}

/**
 * Registers the `core/calendar` block on server.
 */
function register_block_core_calendar() {
	register_block_type_from_metadata(
		__DIR__ . '/calendar',
		array(
			'render_callback' => 'render_block_core_calendar',
		)
	);
}

add_action( 'init', 'register_block_core_calendar' );