How do I change the start day of my week?

Via the app

1. Tap the blue menu button (next to the search bar in your Diary).
2. Select Diary Preferences > Start Of Week.

Via the website

1. Click Settings (top left just above food diary).
2. Click Set the day my week view starts on.
3. Select the day you want your week to start from the drop down and press the green Apply Changes button.