As far as I only want to modify the format for my mod and nowhere else, can I write something like that in my custom functions_email.php ?

Code:
define('DATE_FORMAT_LONG', '%A %d %B, %Y %T');
 $Emb_Order_Extra = '<table border="0" cellspacing="0" cellpadding="2"  width="275"><tr><td class="main"><strong>' .  ENTRY_DATE_PURCHASED .  '</strong></td></tr><tr><td class="main">' .  zen_date_long($order_check->fields['date_purchased']) .  '</td></tr><tr><td class="main">' .  '<b>Customer comments: </b><br>' . $orders_history->fields['comments'] .  '</td></tr><tr><td class="main"><b>' .  ENTRY_PAYMENT_METHOD .  '</b></td></tr><tr><td class="main">' .  $order->info['payment_method'] .  '</td></tr></table>';
define('DATE_FORMAT_LONG', '%A %d %B, %Y');
i.e. changing the format temporarly and then redefining it as it was before.

Hubert