How long does it take to complete dusk?

Could you elaborate on the term "dusk" in the context of your question? Are you referring to a specific process, such as a transaction or mining block on a cryptocurrency network? If so, the time it takes to "complete dusk" would depend greatly on the specifics of that network and the current conditions. For instance, a transaction on a popular blockchain may take only a few minutes to be confirmed, while mining a new block could take hours or even days. Without more information, it's difficult to give an accurate estimate of how long "dusk" takes to complete.