Hi @acarpenetti Based on my understanding, we might not know the DateandTime value when Business Account extended as Customer.
Acumatica is just updating the LastModifiedDateTime field when Business Account is extended as Customer in the BAccount table. But, in the Customer table, we do not have the CreatedDateTime, LastModifiedDateTime fields and other audit fields to fetch the Date when Customer is extended from Business Account.
However,, we can achieve this with the simple customization. Please find the details below.
We can introduce a new Date and Time field in the Customers screen (read only field) in the header section and this Date field can be automatically populated whenever a Business Account is extended to become a Customer. Please let me know if you need further assistance on this.