Provide timezone to Duckling API

[nioc]

Is your feature request related to a problem? Please describe.
I would like to use Duckling for handling date and duration but I can not provide the timezone, so the returned value is in the default (UTC-7) and

Describe the solution you'd like
Duckling parse API can handle timezone in a tz parameter, it should be useful that the BuiltinDuckling sent it (using the system one or a NER config attribute).

Describe alternatives you've considered
None.

Additional context
I'm using the Duckling Rasa docker which is not using the TZ environment variable.

Same issue on Rasa which was handled

This example show my request:

{
    "text": "shutodwn at 23:15",
    "tz": "Europe/Paris",
    "locale": "fr_FR"
}

Without the tz parameter Duckling answer 2023-08-16T23:15:00.000-07:00:

[
  {
    "body": "23:15",
    "start": 12,
    "value": {
      "values": [
        {
          "value": "2023-08-16T23:15:00.000-07:00",
          "grain": "minute",
          "type": "value"
        },
        {
          "value": "2023-08-17T23:15:00.000-07:00",
          "grain": "minute",
          "type": "value"
        },
        {
          "value": "2023-08-18T23:15:00.000-07:00",
          "grain": "minute",
          "type": "value"
        }
      ],
      "value": "2023-08-16T23:15:00.000-07:00",
      "grain": "minute",
      "type": "value"
    },
    "end": 17,
    "dim": "time",
    "latent": false
  }
]

With tz parameter, answer is correct (2023-08-17T23:15:00.000+02:00):

[
  {
    "body": "23:15",
    "start": 12,
    "value": {
      "values": [
        {
          "value": "2023-08-17T23:15:00.000+02:00",
          "grain": "minute",
          "type": "value"
        },
        {
          "value": "2023-08-18T23:15:00.000+02:00",
          "grain": "minute",
          "type": "value"
        },
        {
          "value": "2023-08-19T23:15:00.000+02:00",
          "grain": "minute",
          "type": "value"
        }
      ],
      "value": "2023-08-17T23:15:00.000+02:00",
      "grain": "minute",
      "type": "value"
    },
    "end": 17,
    "dim": "time",
    "latent": false
  }
]

A rapid fix for this should be in the builtin-duckling request function:

      const postData = querystring.stringify({
        text: utterance,
        locale: BuiltinDuckling.getCulture(language),
        tz: Intl.DateTimeFormat().resolvedOptions().timeZone,
      });

[nioc]

As a workaround, I created a custom-duckling.js which extends BuiltinDuckling:

const { BuiltinDuckling } = require('@nlpjs/builtin-duckling')
const querystring = require('querystring')

class CustomDuckling extends BuiltinDuckling {
  constructor (settings = {}) {
    super(settings)
  }

  request (utterance, language) {
    return new Promise((resolve, reject) => {
      const postData = querystring.stringify({
        text: utterance,
        locale: BuiltinDuckling.getCulture(language),
        tz: Intl.DateTimeFormat().resolvedOptions().timeZone,
        lang: language.toUpperCase(),
      })

      const options = {
        host: this.url.hostname,
        port: this.port,
        method: 'POST',
        path: this.url.pathname,
        headers: {
          'Content-Type': 'application/x-www-form-urlencoded',
          'Content-Length': postData.length,
        },
      }
      const req = this.client.request(options, (res) => {
        let result = ''
        res.on('data', (chunk) => {
          result += chunk
        })
        res.on('end', () => {
          try {
            const obj = JSON.parse(result)
            resolve(obj)
          } catch (err) {
            reject(err)
          }
        })
        res.on('error', (err) => reject(err))
      })
      req.on('error', (err) => reject(err))
      req.write(postData)
      req.end()
    })
  }
}

module.exports = CustomDuckling

Called at application start:

const CustomDuckling = require('./custom-duckling')

manager = new NlpManager({...})
manager.container.register('extract-builtin-??', new CustomDuckling({
  ducklingUrl: 'http://localhost:8000/parse',
}), true)

There is a downside in case the BuiltinDuckling request method changes...

[MarketingPip]

@nioc - not an official maintainer / nor contributor. Just frequent user of this library, hate to see it die.

That said - no way you could possibly dig into the request method to see if your required changes could be implemented without any breaking changes? If so - I suggest obviously making a PR for this. As I am sure a lot of people are wanting this.

[nioc]

Hello @MarketingPip I think a timezone parameter should be added in settings object provided to constructor.
I can do a PR, but before I'm waiting a validation from any owner/maintainer.

[MarketingPip]

@nioc completely agree. That said - let's see if I can make a bump on your behalf so we can get approval on this.

@jseijas - can you give a confirm on this? (Don't mean to jack the issues - but trying to help solve / close some!)