---
title: timestampExtract
description: Pipeline expression helper that extracts a calendar part from a timestamp.
next: /firestore/pipelines/subcollection
previous: /firestore/pipelines/timestamp-diff
---

`timestampExtract()` reads a calendar component—such as `year`, `month`, or `day`—from a timestamp. An optional timezone shifts the calendar used for extraction.

Import from the pipelines entry point:

```js
import { timestampExtract, field } from '@react-native-firebase/firestore/pipelines';
```

# Basic example

```js
import { getFirestore } from '@react-native-firebase/firestore';
import { execute, field, timestampExtract } from '@react-native-firebase/firestore/pipelines';

const db = getFirestore('your-enterprise-database-id');

const snapshot = await execute(
  db
    .pipeline()
    .collection('events')
    .select(
      timestampExtract(field('createdAt'), 'year').as('createdYear'),
      timestampExtract('createdAt', 'month').as('createdMonth'),
      field('createdAt').timestampExtract('day').as('createdDay'),
    ),
);

snapshot.results.forEach(row => {
  console.log(row.data().createdYear, row.data().createdMonth, row.data().createdDay);
});
```

# Related helpers

| Helper              | Use when                                      |
| ------------------- | --------------------------------------------- |
| `timestampExtract`  | Read year, month, day, or other calendar part |
| `timestampTruncate` | Bucket timestamps to a granularity            |
| `timestampDiff`     | Measure elapsed time between timestamps       |
| `TimePart`          | Type for part literals such as `'year'`       |

# Upstream reference

See the [firebase-js-sdk `timestampExtract` declaration](https://firebase.google.com/docs/reference/js/firestore_pipelines#timestampextract) for full overload signatures and supported `TimePart` values.