# Sleep For A Duration Many languages allow you to sleep for a certain number of milliseconds. In those languages, you can give `500` or `1000` to the sleep function to sleep for half a second and a second respectively. In Go, the duration of a call to [`time.Sleep`](https://golang.org/pkg/time/#Sleep) is in nanoseconds. Fortunately, there are constants that make it easy to sleep in terms of milliseconds. For example, you can sleep for a half a second (500 milliseconds) like so: ```go package main import ( "time" ) func main() { time.Sleep(500 * time.Millisecond) } ``` Other available time constants are `Nanosecond`, `Microsecond`, `Second`, `Minute`, `Hour`.