aws ec2 describe-snapshots --query "sort_by(Snapshots, &StartTime)[-1].{SnapshotId:SnapshotId,StartTime:StartTime}"
{
"SnapshotId": "snap-123456",
"StartTime": "2020-07-07T13:57:05.982Z"
}
MY_ACCOUNT_ID=123456789 aws ec2 describe-snapshots --filter "Name=owner-id,Values=$MY_ACCOUNT_ID" --query "sort_by(Snapshots, &StartTime)[-1].{SnapshotId:SnapshotId,StartTime:StartTime}"