---
title: Date Difference Custom Value
slug: segment/date-difference-custom-value
docTags: 
createdAt: 2026-01-16T18:04:12.803Z
---

Date Difference Custom Value (also known as the DATEDIFF() in SQL) allows you to calculate the difference between two date fields and express the difference into a specific time unit of your choice.

This can be a calculation between either:

- Two existing date fields from a Selected Data Extension
- A timestamp and an existing date field from a Selected Data Extension (and vice versa)

## Video overview

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## Create a Date Difference Custom Value

1. Under **Custom Values**, click the **Add new value** button.
2. Provide a name for the Custom Value, select *Apply formula to a field* as **Type**, and click **Next.**

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3. Select *Date Difference* as **Type of Formula **and click **Next.**

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4. Select either the date fields or the timestamp that you want to calculate and the time unit you want to express the difference in.

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5\. Click **Save** and move the new Custom Value to the Target Data Extension fields.