Smarty if statement with date & date = month > to show results

Question

I got table from array and many amounts $$$ for different dates.

Example:

-08/10/2015 | Amount: 2500$
-19/10/2015 | Amount: 1000$
-20/11/2015 | Amount: 500$
-27/11/2015 | Amount: 720$
-30/12/2015 | Amount: 100$
-31/12/2015 | Amount: 250$

My current code in the smarty template is:

                {foreach from=$referrals item=referral}
                    {if $referral.date eq "08/10/2015"}
                            {assign var="sum" value="`$sum+$referral.amount`"}
                    {/if}
                {/foreach}
                    <td>{$sum|number_format:2:",":"."} ден.</td>
                {assign var="sum" value=0}

And i only get total amount only for date: 08/10/2015

My question is how to get total amount for the whole month (10) October, or for the whole month (11) November and for whole year separated by months and only for amounts that are not 0 (zero), because i have that kind of amounts as well?

And this is my array (containing more than 136 arrays):

Smarty_Variable Object (3)
->value = Array (137)
  0 => Array (11)
    id => "1514"
    date => "05/01/2016"
    service => "Рамка со податоци"
    package => "Рамка со податоци"
    userid => "500"
    amount => "0.00"
    billingcycle => "One Time"
    amountdesc => "0,00 ден. One Time"
    commission => "0,00 ден."
    lastpaid => "Never"
    status => "Active"
  1 => Array (11)
    id => "1515"
    date => "05/01/2016"
    service => "Лого со податоци"
    package => "Лого со податоци"
    userid => "500"
    amount => "0.00"
    billingcycle => "One Time"
    amountdesc => "0,00 ден. One Time"
    commission => "0,00 ден."
    lastpaid => "Never"
    status => "Active"
  2 => Array (11)
    id => "1496"
    date => "29/12/2015"
    service => "Рамка со податоци"
    package => "Рамка со податоци"
    userid => "493"
    amount => "0.00"
    billingcycle => "One Time"
    amountdesc => "0,00 ден. One Time"
    commission => "0,00 ден."
    lastpaid => "Never"
    status => "Active"
  3 => Array (11)
    id => "1497"
    date => "29/12/2015"
    service => "Лого со податоци"
    package => "Лого со податоци"
    userid => "493"
    amount => "0.00"
    billingcycle => "One Time"
    amountdesc => "0,00 ден. One Time"
    commission => "0,00 ден."
    lastpaid => "Never"
    status => "Active"
  4 => Array (11)
    id => "1498"
    date => "29/12/2015"
    service => "Реклама во црно-бела техника на 1/6 -..."
    package => "Реклама во црно-бела техника на 1/6 -..."
    userid => "493"
    amount => "0.00"
    billingcycle => "One Time"
    amountdesc => "0,00 ден. One Time"
    commission => "0,00 ден."
    lastpaid => "Never"
    status => "Active"
  5 => Array (11)
    id => "1500"
    date => "29/12/2015"
    service => "Лого и мапа на www.abv.mk"
    package => "Лого и мапа на www.abv.mk"
    userid => "493"
    amount => "0.00"
    billingcycle => "One Time"
    amountdesc => "0,00 ден. One Time"
    commission => "0,00 ден."
    lastpaid => "Never"
    status => "Active"

Answer 1

*//sum for october month*

{assign var="sum" value=0}

{foreach from=$referrals item=referral}

  {if $referral.date|date_format:"%m" == 10 && $referral.amount != 0}

     {assign var="sum" value=$sum+$referral.amount}

  {/if}

{/foreach}

*//display sum*

{$sum|number_format:2:",":"."}