Adding due dates to cards
You can set a date and time for when a card is "due". A badge with the due date will appear on the card. A light grey badge means the card is due more than 24 hours in the future, yellow badge means it's within 24 hours of being due, a red badge means the card is due and it will remain red for 24 hours, a light pink badge means it's past due, and a green badge means it's complete.
You can add a due date via the card back under "Add" in the card's sidebar. You can also add dates via the card menu on the front of the card or by hovering your mouse over a card and using the "d" shortcut, or in the quick edit menu by clicking the pencil icon when hovering your mouse over a card.
You can edit a due date by clicking the due date on the card back and selecting a new date or time.
Marking a due date as complete
On the card back, you can click the checkbox next to the due date to mark it as complete, and turn the due date green. This will also add a strikethrough on the card on the Calendar View.
Remove a due date by clicking the due date on the card back and selecting "Remove" from the lower right corner.
If you are subscribed to a card, you will receive a notification 24 hours before the card is due.
You can use "d" to open the date picker and add, edit, or remove a date and time via the board view.
Bonus: If you have the calendar power-up enabled you can view all of your cards with due dates in a calendar view. See: Viewing cards in a calendar view