[預開票日] => DateTime Object ( [date] => 2019-03-17 00:00:00.000000 [timezone_type] => 3 [timezone] => PRC )
[預收款日] => DateTime Object ( [date] => 2019-04-01 00:00:00.000000 [timezone_type] => 3 [timezone] => PRC )
判斷是日期格式用
echo "{$key} -> ".date_format($val,"Y-m-d") ." <br />";
還是不行. 請問怎樣轉換格式謝謝.