仅在今天显示Sum（）

I need to show total amount only for today. Tomorrow only for tomorrow and etc.. Here is my code:

<div class="num" data-postfix="" data-duration="1500" data-delay="0">

<?php
    include ("db_connection.php");

    $sql=mysqli_query($mysqli,"SELECT SUM(deposit_amount - deposit_charge) 
    AS 'deposit_today' 
    FROM incomes 
    WHERE date_time >= DATE_SUB(NOW(), INTERVAL 1 DAY)");

    while($arow=mysqli_fetch_array($sql)){
    ?>

    <p> <?php echo $arow['deposit_today']; ?> </p>

    <?php 
    }
    ?>
</div>

But it show me only SUM(deposit_amount - deposit_charge) for all dates.