The date format changes the displayed date in the document list and on the documents.
IMPORTANT NOTE: If you want to change the date format on your sent documents via Billdu, you have to change it on the website.
Your current date/time format and time-zone are based on your device setting. On iOS devices navigate to Settings - General - Language & Region - Region. You can see a date and number format as an example.
For a fast change to common date formats, navigate to your iOS Settings, locate the Billdu app, and find the Preferred language setting. Select different languages to change the date format of your invoices instantly.
On Android devices, it can be found mostly at Settings - System. Please see the instructions for your mobile device in case you need to change some date/time or time-zone settings.
You can change your date/time format and your time-zone under Settings - Template design and settings - Local settings. Change the Regional settings.
The date format changes for your online invoices as well.