is it possible to use JSON Numeric aggregation functions in API gateway map

Question

As the subject says, I am looking if it is possible to use JSON Numeric aggregation functions in API gateway mapping templates?  
I have the below template and I would want to add the "ttl" column as a future date.   
{  
  "TableName": "api",  
  "Item": {  
    "ingestId": {  
      "S": "$context.requestId"  
    },  
    "ttl": {  
      "N": "$context.requestTimeEpoch"  
    }  
  }  
}  
  
So I wanted to try the sum() function of the request Epoch time and some number to get a future date as the result.  
Any suggestions and inputs are welcome.

Answer

I had to use the set variable before the JSON structure. I was trying it inside and was failing at the syntax validation.   
#set($milliseconds = $context.requestTimeEpoch + 2*86400000)  
  
This sets the milliseconds variable to current epoch + 2 days and this variable can be used in subsequent JSON.

is it possible to use JSON Numeric aggregation functions in API gateway map

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