This command will delete all PODs older than one day :

kubectl get pods -o go-template --template '{{range .items}}{{.metadata.name}} {{.metadata.creationTimestamp}}{{"\n"}}{{end}}' | awk '$2 <= "'$(date -d 'yesterday' -Ins --utc | sed 's/+0000/Z/')'" { print $1 }' | xargs --no-run-if-empty kubectl delete pod

This command will delete all PODs older than 4 hours :

kubectl get pods -o go-template --template '{{range .items}}{{.metadata.name}} {{.metadata.creationTimestamp}}{{"\n"}}{{end}}' | awk '$2 <= "'$(date -d'now-4 hours' -Ins --utc | sed 's/+0000/Z/')'" { print $1 }' | xargs --no-run-if-empty kubectl delete pod

We could this with only awk by doing a regex [0-9]+d directly on the AGE ($5, 5th column) column and then printing the corresponding NAME ($1, first column) column

kubectl delete pod $(kubectl get pod | awk 'match($5,/[0-9]+d/) {print $1}')

Test first to see what's matching:

kubectl get pod | awk 'match($5,/[0-9]+d/) {print $0}'

$0 means all columns

You can either add a liveness probe to track how long the pod alive and kill it when it's longer a certain period. Or you can schedule a CronJob