How can i get the below command working.

```
export CURDATE=`date +%Y-%m-%d`
curl -XPOST "http://localhost:9200/test/type" \
  -d ' { "AlertType": "IDLE", "@timestamp": $CURDATE }'

```

I am getting error "reason":"Unrecognized token '$CURDATE': was expecting"
How do i get the variable substitution correct in the code above