Format Date

/**

 * Change the date format of the "Date of Donation" column in the Donations export.

 *

 * @param  mixed  $value The value to set.

 * @param  string $key   The key to set.

 * @param  array  $data  The set of data.

 * @return mixed

 */

function ed_charitable_format_date_in_donation_export( $value, $key, $data ) {

    if ( 'date' == $key ) {

        /**

         * You can use any valid date format.

         *

         * @see http://php.net/manual/en/function.date.php

         */

        $value = charitable_get_donation( $data['donation_id'] )->get_date( 'd/m/Y' );

    }

    return $value;

}

add_filter( 'charitable_export_data_key_value', 'ed_charitable_format_date_in_donation_export', 20, 3 );