You'll want to review the invoice template you're using to ensure every detail appears when you email it to your clients, @StanleyQ. I'll go over the details below.

If you're using the Modernized template, please ensure that you add the Service Date field from the Table content of your invoice. Here's how:

1. Navigate to your invoice transaction.
2. A window appears in the left pane. Select the Design dropdown.
3. Check if you've selected Modern under the Modernized template section.
4. Once done, select the Customization dropdown.
5. Enable the Service date option in the Table content.
   
6. Click Print and download to preview your invoice.

Otherwise, you can update the invoice template so that it will show up when you print or send the invoice to your clients. Here's how:

1. From the Design dropdown, select Add/Edit next to Other templates.
   
2. Click Edit for the template you're using.
3. Choose the Content tab.
4. Select the Table section, and ensure to tick the Date checkbox.
5. Tap Done to save the template.
   

Moreover, you'll want to visit this article that outlines how to document your invoice payments to keep correct financial records: Record invoice payments in QuickBooks Online.

Please keep me informed by commenting below if there's anything else you need assistance with regarding adding dates to your invoices. I'm always available to share helpful information and resources.