title: Find date value in an array in PHP
body: <p>I have dates stored in an array but defining date ranges in a special format like this :</p>
  
  <pre><code>Array
  (
      [0] =&gt; Array
          (
              [0] =&gt; Array ///date start
                  (
                      [0] =&gt; 2017
                      [1] =&gt; 10 //month
                      [2] =&gt; 3 //day
                  )
  
              [1] =&gt; Array //date end
                  (
                      [0] =&gt; 2017
                      [1] =&gt; 10 //month
                      [2] =&gt; 5 //day
                  )
  
          )
  
      [1] =&gt; Array
          (
              [0] =&gt; Array //date start
                  (
                      [0] =&gt; 2017
                      [1] =&gt; 11
                      [2] =&gt; 23
                  )
  
              [1] =&gt; Array //date end
                  (
                      [0] =&gt; 2017
                      [1] =&gt; 11
                      [2] =&gt; 25
                  )
  
          )
  
  )
  </code></pre>
  
  <p>And I would need a function that can return if a specific string date exist in the array</p>
  
  <pre><code>2017-10-01. is_in_array ('2017-10-01').
  </code></pre>
  
  <p>But I don't understand how can I do with the foreach  and the special array format of the date ranges.</p>