# Day() Function
**YouTube:** [How to Use the Day Function in Report Custom Columns ?](https://www.youtube.com/watch?v=5-oonlBNFX8)
## How to Use the Day Function in Report Custom Columns?
In this tutorial, we’ll learn how to use the `Day` function in expression design to extract the **day number** (e.g., 1 to 31) from a date field such as *Bill Date* within a report.
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### Accessing the Expression Designer:
* Navigate to the **Reporting** section.
* Open the **Sales Register Detailed Report** or any **"Report".**
* Go to **Setup Column Attributes**.
* Here, you'll see a list of available columns that can be used to build expressions.
* Click on **"Add/Edit Expression Columns"** where you can write your expression using predefined functions.
* Before adding the expression to the report, go to **Other Settings**.
* Ensure the **Script Editor** is set to **VBScript**.
* Click **Save**.
* *Note: VBScript is the default for new configurations but always verify this setting.*
### Writing Your First Expression
* Every expression must start with the script header: **'#@LSCRIPT**
* Click the (+) Plus icon to create a new expression.
* Fill in the required fields:
* **Expression Name** – A unique name for your expression.
* **Expression Type** – Choose either **Text** or **Numeric** depending on the expected output.
* Double-click the new expression name to insert it into the script editor.
* Define the expression using the syntax:
* **Expression Name** = DAY(CDATE(BILL\_DATE))
* `Day(...)` returns the day component from the date (e.g., 5 for 5th June).
* `CDate(BILL_DATE)` converts the string into a valid date.
* Click **Save**.
* Scroll down and **check the box** to enable the column in the report.
* Save and proceed to check the effect.
* **Refresh the report** to view the final result.
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### Output:
The newly added column now displays the **day number** extracted from the *Bill Date*.\
For example: if the bill date is `09-Jun-2025`, the output will be `9`.
