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How to Calculate Dates and Validate Required Fields in Microsoft Lists

Maira Mehtab Sep 21, 2026 868 views

Question details

The user needs a way to calculate a date in one column based on another column (e.g., subtracting nine days) and block users from filling out later fields if an earlier required field is left blank in Microsoft Lists.

Product: Microsoft Lists / SharePoint
Device & OS: not provided
Scenario: Automating date column calculations and enforcing conditional column validation rules to maintain data integrity.
Observed behavior: Looking for solutions because out-of-the-box calculated columns do not support cross-list lookups for dates, and dependent column validation requires specific syntax.

Before you start

Ensure you have List Owner or Site Owner permissions to access the List Settings menu and apply validation formulas to your Microsoft List.

Solution 1Recommended

Validate Fields Using List Settings

Set up list-level validation rules to prevent users from completing subsequent columns when an earlier required column is empty.

This method uses standard SharePoint and Microsoft Lists formula syntax to evaluate column conditions before allowing an item to be saved.

Open List Settings

Navigate to your Microsoft List, click the gear icon in the top right corner to open Settings, and select 'List settings'.

Access Validation Settings

Under the 'General Settings' section, click on 'Validation settings'.

Enter the Validation Formula

To prevent Column 10 from being completed when Column 9 is empty, type the following formula into the Formula box: =IF(Column9="",IF(Column10="",TRUE,FALSE),TRUE)

Save Your Changes

Add a clear user message below the formula (e.g., 'Please fill out Column 9 first'), and click 'Save' to apply the rule.

Formula Logic: This formula allows the item to be saved when Column 9 contains a value, or when both columns are empty. It correctly triggers an error if Column 10 has a value while Column 9 is blank.

Solution 2

Use Power Automate for Date Calculations

Since Microsoft Lists does not provide a native way to calculate a date from another list or lookup column, use Power Automate to handle the logic.

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Manage Data Easily with WPS Spreadsheet

While Microsoft Lists requires complex workarounds for basic date calculations and dependent column validations, managing your tracking data in a spreadsheet is often much faster and more intuitive. WPS Office offers a free, lightweight alternative with advanced data validation and formula capabilities.

1. Download and Install WPS Office: Get WPS Office from the official website and install it on your device.
2. Open WPS Spreadsheet: Launch WPS Spreadsheet and either open your exported List data or start a new tracker.
3. Apply Data Validation: Navigate to the Data tab and click Data Validation to easily restrict inputs based on other cells.

Easily calculate dates using simple spreadsheet formulas like =A2-9 without requiring external flows.Set up strict Data Validation rules in seconds through an intuitive interface.Fully compatible with Microsoft Excel (.xlsx) formats for easy migration.Free, lightweight, and features a familiar user interface.

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Frequently Asked Questions

Can I use a Calculated Column to pull a date from a Lookup column in Microsoft Lists?

No, SharePoint and Microsoft Lists do not support referencing Lookup columns directly within out-of-the-box Calculated Columns. You must use Power Automate to pull the value and write it back to your list.

Why is my list validation formula throwing a syntax error?

Ensure that your formula uses the exact internal column names, which can sometimes differ from their display names if they were renamed. Also, verify that all parentheses and commas are correctly placed according to standard Excel-like syntax.

How do I make a column conditionally required based on another column's value?

You can achieve this by navigating to List Settings > Validation Settings and writing an IF formula that checks the value of the first column. The formula must evaluate to FALSE if the second column is empty when your condition is met.

Can I do simple date math in a standard SharePoint calculated column?

Yes, if both columns are standard fields (not lookups) within the same list, you can use simple arithmetic in a Calculated Column, such as =Column1-9 to subtract nine days.

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