Getting Current date in Painless

I want to get the difference of current today and another date field as 'age' field.(new field)
So i was trying to add a dynamic script field in elastic search.Below is the query i used

curl -XPOST 'localhost:9200/test8/_search' -H 'Content-Type: application/json' -d '{
 "query": {

  "query": {
    "match_all": {}
 "_source" : [],
  "script_fields": {
    "age1": {
      "script": "(Date().getTime()- doc['Request Date'].value)/(24*60*60*1000)"

But i get this error "Variable [DateTime] is not defined.
Seems like Date().getTime() cannot fetch the current date in painless
Could anyone let me know what is the syntax to get current date in painless.
I am using elastic search 7.6.0 and kibana 7.6.0
Thanks in advance

Please wrap your code with ``` so that it is readable.