PHP-Date Matching，带有CurrentDayDate的DataBaseDate

I have made a calendar in zend-framework2, and i want to show a specific event on a specific date, onto the calendar. This is the picture of calendar.

I want to set an if condition, that if true will show the event on the Calendar.

This is what i have tried yet...

<?php if($this->activity['activityCreated'] == $running_day):?>

    <p>hello</p>

<?php endif; ?>

$running_day is the current day, and it's code is,

$running_day = date('w', mktime(0, 0, 0, $this->month, 1, $this->year));

So how do I match/compare database date with $running_day date?