# Date/time formatting

iSHARE adopts internationally recognised standards for expressing dates and times:

* **UTC (Coordinated Universal Time)** – Time standard unaffected by time zones or daylight saving time.
* **Unix Timestamp** – The number of seconds elapsed since the Unix epoch (1970-01-01T00:00:00Z, UTC).
  * *Example:* `1536089675` represents **2018-09-04T19:34:35Z**.
* **RFC3339 /** **ISO 8601 Date-Time Format** – A human-readable and machine-parseable representation of date and time in UTC, using the Z suffix (as defined in [ISO 8601](https://www.iso.org/iso-8601-date-and-time-format.html) and [RFC 3339](https://www.rfc-editor.org/rfc/rfc3339.html)).
  * *Example:* `2025-09-22T14:05:30.123Z`.

**Requirement**\
All date-time values **MUST** be expressed in UTC and **MUST** follow the ISO 8601 extended date-time format with milliseconds, and the `Z` UTC indicator, e.g. `YYYY-MM-DDTHH:MM:SS.sssZ`.

Unless explicitly specified, ISO8601 date-time in UTC is the default format. An exception is, for example, the [iSHARE JWT](https://dev.ishare.eu/reference/ishare-jwt), which specifies the use of a Unix Timestamp (in line with the JWT standard).


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://dev.ishare.eu/introduction/specific-technical-standards/utc.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.