The top bar
The top bar shows the chart you're on, the moment you're on, and the place you're observing from.
While you're on the present it reads "Now". When you move to another date it changes, and offers the way back: click it, or press ⌘. , to return to the current sky.
The place you're observing from is separate from the chart, so you can look at the current sky from another city without changing your saved home location.
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