I'm trying to obtain the creation date of a card without success and I don't see any fields with this information in the API. Is there anything else than the date of the last activity on the card?
Thanks
You should be able to find it by adding card_actions=all (or more specifically, card_actions=createCard) to the request url.
The full ID for every object has additional information embedded in it (cards, boards, lists), including the time it was created. The first 8 characters of the hexadecimal id (the first 4 bytes) represent a Unix timestamp, which can then be translated into a date.
For eg. If a board has an ID of 4d5ea62fd76aa1136000000c
Taking the first 8 characters, we get: 4d5ea62f
Converted to a decimal from hexadecimal, the timestamp is: 1298048559
PHP Example
<?php
$cardID = '4d5ea62fd76aa1136000000c';
$createdDate = date('r', hexdec( substr( $cardID , 0, 8 ) ) );
echo $createdDate;
?>