According to http://docs.aws.amazon.com/cli/latest/reference/ec2/describe-images.html and other docs, "aws ec2 describe-images --image-id ami-XXXX" command should provide AMI creation date as part of the output. But for all my AMIs (created using "aws ec2 create-image") I receive "None" instead of creation date. Any suggestions how to debug it?
First step would be to upgrade the version of the aws cli you are using, see https://docs.aws.amazon.com/cli/latest/userguide/installing.html
If that doesn't resolve the issue, then you could ask for AWS help at https://forums.aws.amazon.com/forum.jspa?forumID=150 or if you are paying for support, then submit a Support Case.