#include <date.au3>
$data1 = "10.01.1999"
$data2 = "12.07.2005"
$arr_data1 = StringSplit($data1, ".")
$arr_data2 = StringSplit($data2, ".")
$str_data1 = $arr_data1[3]&"/"&$arr_data1[2]&"/"&$arr_data1[1]
$str_data2 = $arr_data2[3]&"/"&$arr_data2[2]&"/"&$arr_data2[1]
$day_diff = _DateDiff('d', $str_data1, $str_data2)
MsgBox(0, "", "Колличество дней между "&$data1&" и "&$data2&@CRLF&$day_diff)