PHP Taskbook Level 8.6

Given a menu with links. Color the link red if its address matches the URL in the browser address bar.

Given some URL:

$url = 'http://test.com/dir1/dir2/dir3/page.html';

Get the contents of the first folder:

'dir1'

Display the following pyramid on the screen:

xxxxx
xxxx
xxx
xx
x

Given a list of events for specific dates, stored in the following structure:

<?php
	$events = [
		[
			'date' =>  '2019-12-29'
			'event' => 'name1'
		],
		[
			'date' =>  '2019-12-31'
			'event' => 'name2'
		],
		[
			'date' =>  '2019-12-29'
			'event' => 'name3'
		],
		[
			'date' =>  '2019-12-30'
			'event' => 'name4'
		],
		[
			'date' =>  '2019-12-29'
			'event' => 'name5'
		],
		[
			'date' =>  '2019-12-31'
			'event' => 'name6'
		],
		[
			'date' =>  '2019-12-29'
			'event' => 'name7'
		],
		[
			'date' =>  '2019-12-30'
			'event' => 'name8'
		],
		[
			'date' =>  '2019-12-30'
			'event' => 'name9'
		],
	]
?>

Write code that will remake the data structure into this:

[
	'2019-12-29': ['name1', 'name3', 'name5', 'name7'],
	'2019-12-30': ['name4', 'name8', 'name9'],
	'2019-12-31': ['name2', 'name6'],
]