Convert

Understand a date and time and return it as ISO 8601 and epoch

POST/v1/convert/string/date/to/iso_8601

Reads an epoch number (seconds or milliseconds, detected and reported), ISO 8601 text, or a common text format such as 16/10/2026 14:30 or Oct 16, 2026 2:30 PM. Add a format hint to use your own pattern. Text without an offset is read in the time zone you give, and the result is shown in it. Returns ISO text, epoch seconds and epoch milliseconds.

Updated October 27, 2026

Request body

Name	Type	Required	Description
value	string	yes	The date and time as text, or an epoch number
format	string	no	A format hint such as %d/%m/%Y %H:%M. When given, only this format is tried
tz	string	no	Time zone (IANA name such as Europe/Lisbon). Text without an offset is read in it, and the result is shown in it (default `"UTC"`)
day_first	boolean	no	For slashed dates such as 03/04/2026: read the first number as the day (default `false`)

Example request

A request body that works, as JSON.

{
  "value": "13/10/2023 12:00",
  "tz": "Europe/Lisbon",
  "day_first": true
}

Code samples

Replace YOUR_TOKEN with your access token.

curl

curl -X POST 'https://api.skillfulsardine.com/v1/convert/string/date/to/iso_8601' \
  -H 'Authorization: Bearer YOUR_TOKEN' \
  -H 'Content-Type: application/json' \
  --data-raw '{
  "value": "13/10/2023 12:00",
  "tz": "Europe/Lisbon",
  "day_first": true
}'

PowerShell

$body = @'
{
  "value": "13/10/2023 12:00",
  "tz": "Europe/Lisbon",
  "day_first": true
}
'@
$response = Invoke-RestMethod -Method Post -Uri 'https://api.skillfulsardine.com/v1/convert/string/date/to/iso_8601' `
  -Headers @{ Authorization = 'Bearer YOUR_TOKEN' } `
  -ContentType 'application/json; charset=utf-8' `
  -Body ([System.Text.Encoding]::UTF8.GetBytes($body))
$response | ConvertTo-Json -Depth 10

Python

import requests

payload = {
    "value": "13/10/2023 12:00",
    "tz": "Europe/Lisbon",
    "day_first": True,
}

response = requests.post(
    "https://api.skillfulsardine.com/v1/convert/string/date/to/iso_8601",
    headers={"Authorization": "Bearer YOUR_TOKEN"},
    json=payload,
    timeout=30,
)
print(response.json())

JavaScript

const response = await fetch("https://api.skillfulsardine.com/v1/convert/string/date/to/iso_8601", {
  method: "POST",
  headers: {
    "Authorization": "Bearer YOUR_TOKEN",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
  "value": "13/10/2023 12:00",
  "tz": "Europe/Lisbon",
  "day_first": true
}),
});
const result = await response.json();
console.log(result);

Node

// Node 18 or later. Save as call.mjs and run: API_TOKEN=... node call.mjs
const token = process.env.API_TOKEN;

const response = await fetch("https://api.skillfulsardine.com/v1/convert/string/date/to/iso_8601", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${token}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
  "value": "13/10/2023 12:00",
  "tz": "Europe/Lisbon",
  "day_first": true
}),
});
const result = await response.json();
console.log(result);

Rust

// Cargo.toml: reqwest = { version = "0.12", features = ["blocking", "json"] }, serde_json = "1"
fn main() -> Result<(), Box<dyn std::error::Error>> {
    let body: serde_json::Value = serde_json::from_str(r#"{
  "value": "13/10/2023 12:00",
  "tz": "Europe/Lisbon",
  "day_first": true
}"#)?;
    let response = reqwest::blocking::Client::new()
        .post("https://api.skillfulsardine.com/v1/convert/string/date/to/iso_8601")
        .bearer_auth("YOUR_TOKEN")
        .json(&body)
        .send()?;
    println!("{}", response.text()?);
    Ok(())
}

Swift

import Foundation

var request = URLRequest(url: URL(string: "https://api.skillfulsardine.com/v1/convert/string/date/to/iso_8601")!)
request.httpMethod = "POST"
request.setValue("Bearer YOUR_TOKEN", forHTTPHeaderField: "Authorization")
request.setValue("application/json", forHTTPHeaderField: "Content-Type")
request.httpBody = Data(#"""
{
  "value": "13/10/2023 12:00",
  "tz": "Europe/Lisbon",
  "day_first": true
}
"""#.utf8)

let (data, _) = try await URLSession.shared.data(for: request)
print(String(decoding: data, as: UTF8.self))

Response

The fields inside data of a successful response.

Name	Type	Required	Description
iso	string	yes	ISO 8601 text with the offset of tz
epoch_seconds	integer	yes	Whole seconds since 1970-01-01 UTC
epoch_milliseconds	integer	yes	Milliseconds since 1970-01-01 UTC
detected	one of: epoch_seconds, epoch_milliseconds, iso, text	yes	epoch_seconds, epoch_milliseconds, iso or text
matched_format	string	no	For text: the format that matched
timezone	string	yes	The time zone of iso

Example response

A real answer from the operation, as JSON. The fields in the table above are inside data.

{
  "data": {
    "iso": "2023-10-13T12:00:00+01:00",
    "epoch_seconds": 1697194800,
    "epoch_milliseconds": 1697194800000,
    "detected": "text",
    "matched_format": "%d/%m/%Y %H:%M",
    "timezone": "Europe/Lisbon"
  },
  "errors": null,
  "meta": {
    "request_id": "b9b51694-1cbc-4690-ab73-fa73e681b0dc",
    "timestamp": "2026-10-27T07:19:42.058969Z",
    "version": "2026-03-26"
  },
  "pagination": null
}

Responses

Status	When it happens
200	Successful Response
400	The body respects the operation schema, but the use case rejected it. Each problem is one ApiError entry
413	The request is larger than the request size limit of the API allows
422	The body does not respect the operation schema. Each problem is one ApiError entry with the code validation_error
500	Something failed inside the server and was not an input problem. The same envelope, errors may be empty