---
title: "DAYSDIFF(A,B)"
slug: "engineeringdatefunction2-10"
updated: 2021-10-14T16:39:01Z
published: 2021-10-14T16:39:01Z
canonical: "docs.datajet.app/engineeringdatefunction2-10"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.datajet.app/llms.txt
> Use this file to discover all available pages before exploring further.

# DAYSDIFF(A,B)

## Date Transform: DAYSDIFF(A,B)

## Returns the number of days difference between two dates, where A is taken away from B

DAYSDIFF(A,B) = B - A

## Purpose

Use this function to calculate:

- The number of days between two dates
- The elapsed time in days between two time-stamps
- The amount of time between an event and a specific date

## Return Value

| Property | Value |
| --- | --- |
| **FieldType** | Integer |
| **FieldSize** | Med |
| **DataType** | Discrete |
| **DataSize** | Short |

```shell
Example Return Value: -N to N 
where 
N is the maximum difference between dates for any individual record
N is an integer
```

![](https://cdn.document360.io/73b6469b-c1e4-47e9-aa65-986c8ebd17ca/Images/Documentation/DAYSDIFF_Sample.PNG)

## Parameters

| Parameter | JSON | Description |
| --- | --- | --- |
| **Table** | “targetTable”: “MyTableName” | The target table on which the new field will be created |
| **Filter** | “dataset”: {DataSet_JSON} | Optional. If a filter is applied, records not in the filter Recordset will be returned as null. |
| **DateTimeFunction** | “p1”: “DAYSDIFF(A,B)” | DAYSDIFF(A,B) |
| **A** | “p2”: “DateTimeFieldName” “p2”: “DateFieldName” “p2”: “#YYYY-MM-DD HH:MM:SS” “p2”: “#YYYY-MM-DD” | Required. Date to subtract from B. *Supports:* - **DataType:** Discrete / Continuous - **Field Type:** Date, DateTime - **Fixed Value:** #YYYY-MM-DD, e.g. #2021-04-05 - **Fixed Value:** #YYYY-MM-DD HH:MM:SS, e.g. #2021-04-05 11:01:08 |
| **B** | “p3”: “DateTimeFieldName” “p3”: “DateFieldName” “p3”: “#YYYY-MM-DD HH:MM:SS” “p3”: “#YYYY-MM-DD” | Required. Comparator Date. *Supports:* - **DataType:** Discrete / Continuous - **Field Type:** Date, DateTime - **Fixed Value:** #YYYY-MM-DD, e.g. #2021-04-05 - **Fixed Value:** #YYYY-MM-DD HH:MM:SS, e.g. #2021-04-05 11:01:08 |

## JSON Sample

![](https://cdn.document360.io/73b6469b-c1e4-47e9-aa65-986c8ebd17ca/Images/Documentation/DAYSDIFF_JSON.PNG)

## Usage Notes

The order in which fields A and B are specified will affect the value of DAYSDIFF(A,B)

See also [ABSDAYSDIFF(A,B)](/v1/docs/engineeringdatefunction2)

## Example

| Example | Details |
| --- | --- |
| **Description** | Calculate the number of days between Purchase and Shipping |
| **Input** | - Table: = [transactions] - Function: = DateTransform - **DateTimeFunction: = DAYSDIFF(A,B)** - A:= [transactions].[dtShipping] - B: = [transactions].[dtPurchase] - Name: =DaysDiff |
| **Sample** | ![](https://cdn.document360.io/73b6469b-c1e4-47e9-aa65-986c8ebd17ca/Images/Documentation/DAYSDIFF_Example.PNG) |