you cannot just change how PHP works.
Usually, events also have a numeric index for more than one "Event".
foreach ($events as $event) {
if ($event['Event']['startDate'] <= $date) {} else {}
}
To access a specific startDate directly, e.g. the first, you would need 0 as key:
if ($events[0]['Event']['startDate'] <= $date) {} else {}
But you cannot abuse foreach this way, though.