Shade Of Night

The Shade Of Night is a device owned and used by Father Time to control the passage of day into night and vice versa. It appeared in the cartoon show episode "Queen Smurfette" when Father Time slept during a fishing trip on the River Of Time and thus forgot about putting an end to the day on Smurfette's birthday until Papa Smurf woke him up to make him remember.

Empath: The Luckiest Smurf stories
In the EMPATH: The Luckiest Smurf story series, it is referred to as the Curtain Of Night, and thus resembles curtains instead of a window shade.