You should be able to copy your entire dairy day as follows:
In our iOS apps and Android app
- Navigate to the diary day you wish to copy
- Tap the "Edit" or Pencil button
- Tap "Select All" at the top of the diary. If you wish, you may de-select some food items by tapping their checkmarks.
- Tap the "Copy" button (two calendar pages) and select the date to which you are copying.
On the web
There is currently not a way to move an entire day's entries, however we will definitely consider adding this for a future update. For now, you can copy each meal from one day to another using the Quick Tools menu (website) or "wrench icon" (apps), then delete the items from the original diary day.