---
title: Datetime now
description: Under most Painless contexts the current datetime, now, is not supported. There are two primary reasons for this. The first is that scripts are often...
url: https://www.elastic.co/docs/reference/scripting-languages/painless/painless-datetime-now
products:
  - Elasticsearch
  - Painless
applies_to:
  - Elastic Cloud Serverless: Generally available
  - Elastic Stack: Generally available
---

# Datetime now
Under most Painless contexts the current datetime, `now`, is not supported. There are two primary reasons for this. The first is that scripts are often run once per document, so each time the script is run a different `now` is returned. The second is that scripts are often run in a distributed fashion without a way to appropriately synchronize `now`. Instead, pass in a user-defined parameter with either a string datetime or numeric datetime for `now`. A numeric datetime is preferred as there is no need to parse it for comparison.

## Datetime now examples

- Use a numeric datetime as `now`
  - Assumptions:
    - The field `input_datetime` exists in all indexes as part of the query
    - All indexed documents contain the field `input_datetime`
  - Mappings:
    ```JSON
    {
      "mappings": {
          ...
          "properties": {
            ...
            "input_datetime": {
            "type": "date"
          }
          ...
        }
        ...
      }
    }
    ```
    
  - Input:
    ```JSON
    ...
    "script": {
        ...
        "params": {
            "now": <generated numeric datetime in milliseconds since epoch>
        }
    }
    ...
    ```
    
  - Script:
    ```java
    long now = params['now'];
    ZonedDateTime inputDateTime = doc['input_datetime'];
    long millisDateTime = inputDateTime.toInstant().toEpochMilli();
    long elapsedTime = now - millisDateTime;
    ```
    
- Use a string datetime as `now`
  - Assumptions:
    - The field `input_datetime` exists in all indexes as part of the query
    - All indexed documents contain the field `input_datetime`
  - Mappings:
    ```JSON
    {
      "mappings": {
        ...
        "properties": {
          ...
          "input_datetime": {
            "type": "date"
          }
          ...
        }
        ...
      }
    }
    ```
    
  - Input:
    ```JSON
    ...
    "script": {
        ...
        "params": {
            "now": "<generated string datetime in ISO-8601>"
        }
    }
    ...
    ```
    
  - Script:
    ```java
    String nowString = params['now'];
    ZonedDateTime nowZdt = ZonedDateTime.parse(nowString); 
    long now = ZonedDateTime.toInstant().toEpochMilli();
    ZonedDateTime inputDateTime = doc['input_datetime'];
    long millisDateTime = zdt.toInstant().toEpochMilli();
    long elapsedTime = now - millisDateTime;
    ```