# BT-2 — Invoice issue date

> https://billhorse.com/en/terms/bt-2/

Date the invoice was issued. UBL expects ISO format YYYY-MM-DD; CII uses a DateTimeString with format="102" (YYYYMMDD).

## Where does it live in the XML?

- UBL: `cbc:IssueDate`
- CII: `rsm:ExchangedDocument/ram:IssueDateTime/udt:DateTimeString`

## Checked by these rules

- [BR-03 — Issue date missing](https://billhorse.com/en/rules/br-03/)
- [BH-DATE-01 — Invalid issue date](https://billhorse.com/en/rules/bh-date-01/)