# Document date

Source: https://developer.avalara.com/erp-integration-guide/transactions/certification-requirements/document-date/

**Element type:** Required

**Endpoints/models used:** [CreateTransactionModel](https://developer.avalara.com/api-reference/avatax/rest/v2/models/CreateTransactionModel/)

Your integration must provide a way for users to enter the document date. This is accomplished using the `date` field in the [CreateTransactionModel](https://developer.avalara.com/api-reference/avatax/rest/v2/models/CreateTransactionModel/). This field indicates the calendar day on which the transaction occurred. Transactions are calculated by the calendar day and aren’t affected by time zones. Whatever the calendar day is locally when you create the transaction, AvaTax will calculate tax according to the tax laws in effect on that calendar day.

The date is essential for determining correctly the tax rules for a transaction. I can be easy to mis-interpret calendar days when a transaction occurs close to a time zone boundary.

[![Closed](https://avalara-devdocs-prod.mcoutput.com/avatax-for-erps/Content/Skins/Default/Stylesheets/Images/transparent.gif)Example](javascript:void\(0\);)

```
{  "type": "SalesInvoice",  "companyCode": "DEFAULT",  "date": "2024-07-16",  "code": "MyDocumentCode",  "customerCode": "ABC",  "purchaseOrderNo": "123456789",  "commit": true,  "currencyCode": "USD",  "description": "Yarn",  ...,} 
```