Daily shows you what notes you've taken on a given day.
Cards will be show up on a given date, depending on whether it's modifiable targeted date (or if a card doesn't have this, date created property) matches the date selected.
The calendar in the sidebar overview, gives you a quick overview of your month. Day objects have a "heatmap" to indicate how many cards you have on any given day. Drag-and-drop is also supported for cards + dates, so you can easily drag a card title onto a different date, setting the new "targeted date" property.
Press the sun icon to jump to today, or the arrow icons to jump between months. Hold down an arrow icon to jump between years.
Quickly switch days
You can quickly change days by clicking on the current date in the top left > "Change Day", or using Ctrl / Cmd + D to type in a new date with your keyboard.