# Querying by Update Timestamp

We provide the query parameter to properly sync all changed data on Dor's server. The query parameter allows API users to query for any records that have been updated since a given timestamp regardless of when that data was recorded on a sensor.

Using this method of querying for data will ensure that all new data is synced, even if it was recorded several hours or days in the past. If any metric has been updated since the last time the user synced (via the provided `updated_at_start` timestamp), that resource will be included in the response.

{% hint style="info" %}
The `updated_at_start` parameter should be provided as a UTC timestamp since it represents a specific point in time. This differs from other timestamp parameters which are grouped by local time. For more information, see [Datetimes](/dtm-docs/dtm-api/datetimes/datetime-formats.md).
{% endhint %}


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# 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://docs.getdor.com/dtm-docs/dtm-api/syncing-data/querying-by-update-timestamp.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.