> For the complete documentation index, see [llms.txt](https://trizen.gitbook.io/sidef-lang/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://trizen.gitbook.io/sidef-lang/programming_tasks/s/sleep.md).

# Sleep

```ruby
var sec = read(Number)        # any positive number (it may be fractional)
say "Sleeping for #{sec} sec..."
Sys.sleep(sec)                # in seconds
#Sys.usleep(sec)              # in microseconds
#Sys.nanosleep(sec)           # in nanoseconds
say "Awake!"
```