How a P&L behaves

Effective dating

A cost that applies from a date forward and leaves history alone.

Where it lives in nouz

Every cost rule in the product.

An effective-dated cost carries the day it takes effect. Saving a new value closes the previous one the day before and opens a new one, so every order stays priced by the rule that was true when it was placed.

Without it, changing a supplier price rewrites last quarter's profit, and any report you ran before the change stops reconciling.

Backdating stays possible, but it is a deliberate act: it reprices the days from that date forward and nothing earlier.

A cost field that holds one value instead of a history is the root of Shopify's COGS report limitations.