Create ICS calendar event file from data.

build_ical.php

<?php

function build_ical( array $input, string $output_path ) {

	$template = file_get_contents( __DIR__ . '/template.ics' );

	$timezone = new DateTimeZone('America/New_York');

	$now   = new DateTime( 'now',           $timezone );
	$start = new DateTime( $input['start'], $timezone );
	$end   = new DateTime( $input['end'],   $timezone );

	$ics = sprintf( $template,
		$end->format('Ymd\THis'),
		md5( $input['name'] ),
		$now->format('Ymd\THis\Z'),
		$input['url'],
		$input['desc'],
		$input['url'],
		$input['name'],
		$now->format('Ymd\THis\Z'),
		$now->format('Ymd\THis\Z'),
		$start->format('Ymd\THis')
	);

	file_put_contents( $output_path, $ics );

}

$example = [
	'name'  => 'My Event',
	'start' => '2022-07-10 14:00',
	'end'   => '2022-07-10 16:00',
	'desc'  => 'This is just the greatest event that ever did event.',
	'url'   => 'https://www.google.com/'
];

build_ical( $example, 'example.ics' );

example.ics

BEGIN:VCALENDAR
VERSION:2.0
CALSCALE:GREGORIAN
BEGIN:VTIMEZONE
TZID:America/New_York
BEGIN:DAYLIGHT
TZOFFSETFROM:-0500
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU
DTSTART:20070311T020000
TZNAME:EDT
TZOFFSETTO:-0400
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:-0400
RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU
DTSTART:20071104T020000
TZNAME:EST
TZOFFSETTO:-0500
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
TRANSP:OPAQUE
DTEND;TZID=America/New_York;VALUE=DATE:20220710T160000
UID:324f6d8407d6852c3f191d929811cdc5
DTSTAMP:20210823T120717Z
LOCATION:https://www.google.com/
DESCRIPTION:This is just the greatest event that ever did event.
SEQUENCE:1
X-APPLE-TRAVEL-ADVISORY-BEHAVIOR:AUTOMATIC
URL;VALUE=URI:https://www.google.com/
SUMMARY:My Event
LAST-MODIFIED:20210823T120717Z
CREATED:20210823T120717Z
DTSTART;TZID=America/New_York;VALUE=DATE:20220710T140000
END:VEVENT
END:VCALENDAR

template.ics

BEGIN:VCALENDAR
VERSION:2.0
CALSCALE:GREGORIAN
BEGIN:VTIMEZONE
TZID:America/New_York
BEGIN:DAYLIGHT
TZOFFSETFROM:-0500
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU
DTSTART:20070311T020000
TZNAME:EDT
TZOFFSETTO:-0400
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:-0400
RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU
DTSTART:20071104T020000
TZNAME:EST
TZOFFSETTO:-0500
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
TRANSP:OPAQUE
DTEND;TZID=America/New_York;VALUE=DATE:%s
UID:%s
DTSTAMP:%s
LOCATION:%s
DESCRIPTION:%s
SEQUENCE:1
URL;VALUE=URI:%s
SUMMARY:%s
LAST-MODIFIED:%s
CREATED:%s
DTSTART;TZID=America/New_York;VALUE=DATE:%s
END:VEVENT
END:VCALENDAR