Allow Posting From/To DateFormula: No More Monthly Date Updates from Business Central v28

 Business Central 28 introduces DateFormula-based posting period fields that automatically calculate your allowed posting range. Here's what changed, how it works alongside the existing fields, and what the code actually does.

The Problem Everyone Knows

If you've worked with Business Central for any length of time, you know the drill. Every month (or every period close), someone has to go into General Ledger Setup and manually update the Allow Posting From and Allow Posting To date fields. Same thing on the User Setup page for individual users who need different posting windows.

 

Miss it, and users can't post. Update it late, and someone might accidentally post into a closed period. It's a small administrative task, but it adds up, and it's surprisingly easy to forget.

What's New in BC28

With Business Central 2026 Release Wave 1 (BC28), Microsoft has added two new fields to both the General Ledger Setup table (Table 98) and the User Setup table:

New Field	Field No.	Type	What It Does
Allow Posting From DateFormula	205	DateFormula	Calculates the start of the allowed posting range dynamically
Allow Posting To DateFormula	206	DateFormula	Calculates the end of the allowed posting range dynamically

These fields use the standard DateFormula data type, the same one you see in payment terms, lead time calculations, and other places across Business Central. The system takes the work date, applies your formula, and determines the allowed posting window automatically.

 

No more monthly manual updates. Set the formula once, and the posting window moves forward on its own.

The Key Rule: DateFormula and Date Fields Are Mutually Exclusive

This is the most important thing to understand about this feature. You can use either the static Date fields or the new DateFormula fields, but not both at the same time. The code enforces this automatically.

How the mutual exclusivity works

If you set a DateFormula value, the system automatically clears the corresponding static Date field (sets it to 0D). And if you set a static Date value, the system automatically clears the corresponding DateFormula field (evaluates it to an empty string).

When you enter a DateFormula (say <-CM>), the trigger checks if the formula is not empty. If it has a value that clears the static date field to blank. Then it validates the date range.

Same thing in reverse. When you enter a specific date (say 03/01/2026), the trigger checks if the new date is not blank. If it has a value, it clears the DateFormula field by evaluating it to an empty string. Clean and simple.

The same pattern applies to the "Allow Posting To" (Field 3) and "Allow Posting To DateFormula" (Field 206) pair. The logic is identical.

 

Bottom line: You don't need to worry about conflicts between the old and new fields. The system handles it. Fill in one, and the other gets cleared automatically. They can coexist on the same page, but only one of each pair will hold a value at any given time.

Practical Example: Setting It Up

Scenario: Monthly Posting Window

Your company wants users to only post within the current month. Previously, you'd set Allow Posting From = 03/01/2026 and Allow Posting To = 03/31/2026 in General Ledger Setup, then remember to change both fields when April starts.

 

Field	Value	Meaning
Allow Posting From DateFormula	<-CM>	Beginning of the current month
Allow Posting To DateFormula	<CM>	End of the current month

With today's date being March 13, 2026, the system calculates:

Allow Posting From = March 1, 2026 (CalcDate of <-CM> from today)

Allow Posting To = March 31, 2026 (CalcDate of <CM> from today)

When April starts, the window automatically becomes April 1 through April 30. No one needs to touch it.

What Happens When You Post Outside the Range?

The error behavior is exactly the same as before. Whether the posting range comes from a static date or a calculated DateFormula, if the posting date on your document falls outside that range, you get the familiar error.

Error

"Posting Date is not within your range of allowed posting dates ...."

Note: Same fields available on User Setup.