What is the 'Zzz' complication on Apple Watch?
It is shown here in an image from a Wired article on the watch before it came out. 
Solution 1:
This is the alarm complication if you choose to snooze an alarm.
It is shown here in an image from a Wired article on the watch before it came out.
This is the alarm complication if you choose to snooze an alarm.