Missing Leading Zero In Date

The XML has following  "Order_Date" tag with Value as below

<ORDER_DATE>08062018</ORDER_DATE>

but when it is being displayed in the Excel  the leading zero is missing  and is being displayed as

8062018

Same way  another Tag   is showing as below in XML

<CONTRACT_NUMBER_MODIFIER>01/08/2018 15:50:57</CONTRACT_NUMBER_MODIFIER>

but when it is being displayed in the Excel  the seconds part is missing

1/8/2018 15:50

I tried giving something like below in the template but did not work.

<?format-date:ORDER_DATE;'MMDDYYYY'?>

How can I modify the format in RTF format to display as required  in the final excel?