Select "[Current Month's] Monthly Issue" from the Welcome Panel to open the Calendar.
Tapping a date on the calendar opens that day's Daily Page. (Future dates cannot be accessed ahead of time.)
Each past date on the Calendar is surrounded by a progress ring. If that day's page has not been started, the ring will be gray. Completed puzzles fill the progress ring in gold, opened but incomplete puzzles fill the bar in cyan. Once all the puzzles on a page have been completed, the date turns into a gold medal on the Calendar.
To access past months, scroll down to "Monthly Issues" in the content menu below the Calendar/Welcome Panel, and tap to select a past month. The selected month will then appear in the Calendar view.
When viewing a page, you can return to the Hub screen by tapping the Home icon in the top left corner. You can also swipe left and right on an open page to browse the other pages in that Monthly Issue.