> For the complete documentation index, see [llms.txt](https://docs.elevateab.com/elevate-helpcenter/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.elevateab.com/elevate-helpcenter/developer-reference/external-api/dates-and-time-zones.md).

# Dates and time zones

How the Elevate A/B Testing External API handles date windows, IANA time zones, paused periods, UTC timestamps, and timeseries buckets.

## Date windows

Results cover every period the experiment ran, with paused periods left out. To look at a narrower window, send both dates:

```plaintext
?startDate=2026-09-01&endDate=2026-09-14&timeZoneName=America/New_York
```

* Dates are `YYYY-MM-DD`, both days included in full.
* `timeZoneName` is an IANA time zone. Without it, dates are in UTC.
* Paused days inside the window stay excluded. `period.dateRanges` in the response shows the periods actually used.

[`/store/overview`](/elevate-helpcenter/developer-reference/external-api/api-reference/store-overview.md) takes the same two dates with its own defaults and limits.

## Timestamps

Timestamps in responses (`createdAt`, `startingAt` and so on) are ISO 8601 in UTC, like `2026-09-01T10:00:00.000Z`.

## Timeseries buckets

`/timeseries` splits the window into buckets aligned to the time zone you send, and each point is keyed by the moment its bucket starts. The bucket size, the modes and what to watch out for are on the [timeseries page](/elevate-helpcenter/developer-reference/external-api/api-reference/timeseries.md).