Wrong date field format on mobile iOS / Android
The solution is not to use :

&lt;input type="date"&gt;


but 

&lt;input type="text"&gt;


With Form API, replace :

$form['my_date'] = array(
    '#type' =&gt; 'date',
);


with

$form['my_date'] = array(
    '#type' =&gt; 'textfield',
);


And attach a date picker like the jQuery Datepicker available in Drupal 8 or other library like Bootstrap Datepicker

In safari, i need to test in private mode because sometines the Safari cache prevents me to see update in my JS.