Source

File: wp-includes/comment-template.php

function get_comment_date( $format = '', $comment_ID = 0 ) {
	$comment = get_comment( $comment_ID );

	$_format = ! empty( $format ) ? $format : get_option( 'date_format' );

	$date = mysql2date( $_format, $comment->comment_date );

	/**
	 * Filters the returned comment date.
	 *
	 * @since 1.5.0
	 *
	 * @param string|int $date    Formatted date string or Unix timestamp.
	 * @param string     $format  The format of the date.
	 * @param WP_Comment $comment The comment object.
	 */
	return apply_filters( 'get_comment_date', $date, $format, $comment );
}