FEEL expression for now() in ISO 8601 format

BPMN & Modeling
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1

I need to produce a timestamp within my workflow corresponding to the current instant in ISO 8601 format:

2025-04-05T11:59:43+00:00

The Camunda 8 implementation of FEEL provides the now() function for this purpose, however based on all of the documentation I can find, it will always be formatted as a zoned date time string:

now()
"2025-04-05T12:08:08.32801833@Etc/UTC"

My aim is to convert the output of now() natively in FEEL to produce a value/string in a format that is in the standard ISO8601 offset-date-time format, and is parseable by the standard java implementation of OffsetDateTime.parse() .

Alternatives I have considered:

  • Converting the string output of now() manually:
replace(string(now()), "@GMT", "Z")

This is very much a bandaid solution, and will obviously not work if the timezone would change for any reason.

  • Creating the correctly formatted date-time string in a dedicated job worker - would work but a lot of unnecessary overhead.

I would appreciate any tips on how I could make this conversion work, or if it is not possible in a reasonable way, to extend FEEL to allow for creating now() in different formats.

2

Hi @matmolni, welcome to the forums! I think I would look at using a DateTimeFormatter and ZonedDateTime when parsing the value in Java, rather than trying to extend the FEEL engine. From there, you can convert it to a LocalDateTime or OffsetDateTime as needed. I think something like this should work:

import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;

public class Main {
  public static void main(String[] args) {
    String datetime = "2025-04-05T12:08:08.32801833@Europe/Berlin";
    DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.nnnnnnnn@VV");
	ZonedDateTime zonedDateTime = ZonedDateTime.parse(datetime, formatter);
    System.out.println(zonedDateTime);
  }
}
3

Depending on where you’re using it, you might try
date and time(now(), "Z")
from the FEEL Documentation

The output I get is:
“2025-04-07T19:09:17.192047466Z”
But the decimal fraction of a second might be too long.

But… It is noted that that is a Camunda Extension, so not guaranteed to work on all FEEL implementations.

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