sundown
n. B2 Upper Intermediate US //ˈsənˌdaʊn// UK //sˈʌndaʊn// sun·down
n. the time of day when the sun goes down and it gets dark. It is often used to describe the end of the workday or a specific time to stop doing something.
n. the period of time when the sun sets and darkness begins. Often used figuratively to refer to the end of a workday or a specific deadline.
The office closes at sundown every Friday.
The campers decided to stop hiking at sundown to avoid the cold and the dark.
While the legal team argued for a strict deadline, the judge suggested that the evidence should be submitted by sundown to allow for a fair review before the weekend.
From sun + down.