﻿---
title: ES|QL DATE_DIFF function
description: 
url: https://www.elastic.co/elastic/docs-builder/docs/2847/reference/query-languages/esql/functions-operators/date-time-functions/date_diff
products:
  - Elasticsearch
---

# ES|QL DATE_DIFF function
## Syntax

![Embedded](https://www.elastic.co/elastic/docs-builder/docs/2847/reference/query-languages/esql/images/functions/date_diff.svg)


## Parameters

<definitions>
  <definition term="unit">
    Time difference unit
  </definition>
  <definition term="startTimestamp">
    A string representing a start timestamp
  </definition>
  <definition term="endTimestamp">
    A string representing an end timestamp
  </definition>
</definitions>


## Description

Subtracts the `startTimestamp` from the `endTimestamp` and returns the difference in multiples of `unit`. If `startTimestamp` is later than the `endTimestamp`, negative values are returned.
**Datetime difference units**

| unit        | abbreviations     |
|-------------|-------------------|
| year        | years, yy, yyyy   |
| quarter     | quarters, qq, q   |
| month       | months, mm, m     |
| dayofyear   | dy, y             |
| day         | days, dd, d       |
| week        | weeks, wk, ww     |
| weekday     | weekdays, dw      |
| hour        | hours, hh         |
| minute      | minutes, mi, n    |
| second      | seconds, ss, s    |
| millisecond | milliseconds, ms  |
| microsecond | microseconds, mcs |
| nanosecond  | nanoseconds, ns   |

Note that while there is an overlap between the function’s supported units and
ES|QL’s supported time span literals, these sets are distinct and not
interchangeable. Similarly, the supported abbreviations are conveniently shared
with implementations of this function in other established products and not
necessarily common with the date-time nomenclature used by Elasticsearch.

## Supported types


| unit    | startTimestamp | endTimestamp | result  |
|---------|----------------|--------------|---------|
| keyword | date           | date         | integer |
| keyword | date           | date_nanos   | integer |
| keyword | date_nanos     | date         | integer |
| keyword | date_nanos     | date_nanos   | integer |
| text    | date           | date         | integer |
| text    | date           | date_nanos   | integer |
| text    | date_nanos     | date         | integer |
| text    | date_nanos     | date_nanos   | integer |


## Examples

```esql
ROW date1 = TO_DATETIME("2023-12-02T11:00:00.000Z"),
    date2 = TO_DATETIME("2023-12-02T11:00:00.001Z")
| EVAL dd_ms = DATE_DIFF("microseconds", date1, date2)
```


| date1:date               | date2:date               | dd_ms:integer |
|--------------------------|--------------------------|---------------|
| 2023-12-02T11:00:00.000Z | 2023-12-02T11:00:00.001Z | 1000          |

When subtracting in calendar units - like year, month a.s.o. - only the fully elapsed units are counted.
To avoid this and obtain also remainders, simply switch to the next smaller unit and do the date math accordingly.
```esql
ROW end_23 = TO_DATETIME("2023-12-31T23:59:59.999Z"),
  start_24 = TO_DATETIME("2024-01-01T00:00:00.000Z"),
    end_24 = TO_DATETIME("2024-12-31T23:59:59.999")
| EVAL end23_to_start24 = DATE_DIFF("year", end_23, start_24)
| EVAL end23_to_end24   = DATE_DIFF("year", end_23, end_24)
| EVAL start_to_end_24  = DATE_DIFF("year", start_24, end_24)
```


| end_23:date              | start_24:date            | end_24:date              | end23_to_start24:integer | end23_to_end24:integer | start_to_end_24:integer |
|--------------------------|--------------------------|--------------------------|--------------------------|------------------------|-------------------------|
| 2023-12-31T23:59:59.999Z | 2024-01-01T00:00:00.000Z | 2024-12-31T23:59:59.999Z | 0                        | 1                      | 0                       |