README update

Author: Mauro Cassani

README.md

@@ -132,7 +132,7 @@ foreach ($qb->getResults() as $element){
 
 ## Working with dates
 
-You can perform queries based on datetime fields. You must specify **date format**:
+You can perform queries based on datetime fields. You must specify **date format** if your format is not `YYYY-mm-dd`:
 
 ```php
 use ArrayQuery\QueryBuilder;

tests/QueryBuilderTest.php

@@ -425,7 +425,7 @@ public function it_should_get_results_from_a_query_with_equals_date()
     {
         foreach ($this->usersArrays as $array) {
             $qb = QueryBuilder::create($array)
-                ->addCriterion('update_date', '2017-08-30', 'EQUALS_DATE', 'Y-m-d')
+                ->addCriterion('update_date', '2017-08-30', 'EQUALS_DATE')
                 ->sortedBy('id', 'ASC');
 
             $results = $qb->getResults();