retrieve last_report older than 30 minutes :
curl -s -G http://localhost:8080/pdb/query/v4/reports --data-urlencode "query=[\"and\",[\"<\",\"receive_time\",\"$(date --utc +%Y-%m-%dT%H:%M -d '30 min ago')\"],[\"=\",\"latest_report?\",\"true\"]]"|jq '.[]| {certname: .certname, receive_time: .receive_time}'