In ccInvoices you will be able to (among other things) configure date format and invoice number format. An explanation about these configuration options can be found in the configuration itself.
- Go to the administrator of the Joomla! website
- Once you are logged in, go to Components > ccInvoices > Configuration
- You now see the configuration of ccInvoices
- Start entering your preferred settings. You can hover over the text to get an explanation of each setting.
If you are using Akeeba Subscriptions with ccInvoices, please also read the chapter about the Invoice # format.