Enter data for the week, instead of daily?

How do i go to another day of the week? I can only enter data  every two days, do i have to enter only on the same day? It doesn't seem to be obvious to me or am i missing something?

Where it say 'today's date' below the log's input area, it also shows dates, type in the dates you want (yesterday) hit enter and the log will refresh the page to show that date. (You can check and see what you ate on a certain date that way)