Sometimes you need more than hourly WordPress events.

CustomWordPressCrons.php

<?php

/*
 * Not only can you reuse this throughout your application for added flexibility but  
 * it gives you added flexibility for scheduling your stuff.
 * The default WordPress cron intervals are, as of this writing:
 *     - Hourly
 *     - Twice Daily
 *     - Daily
*/

add_filter( 'cron_schedules', CustomCronIntervals );
function CustomCronIntervals( $schedules, INT $seconds = 0 ) {

	if( $seconds !== 0 ) {

		$schedules[ "{$seconds}_custom_interval" ] = [
			'interval' => $seconds,
			'display'  => "Once every {$seconds} seconds",
		];

	}

	$schedules[ 'one_minute' ]     = [
		'interval' => 60,
		'display'  => 'Once every minute',
	];
	$schedules[ 'five_minutes' ]   = [
		'interval' => 300,
		'display'  => 'Once every 5 minutes',
	];
	$schedules[ 'ten_minutes' ]    = [
		'interval' => 600,
		'display'  => 'Once every 10 minutes',
	];
	$schedules[ 'thirty_minutes' ] = [
		'interval' => 1800,
		'display'  => 'Once every 30 minutes',
	];

	return $schedules;

}