In computing, sleep is a command in Unix, Unix-like and other operating systems that suspends program execution for a specified time.

The sleep instruction suspends the calling process for at least the specified number of seconds (the default), minutes, hours or days.

[9] Microsoft also provides a sleep resource kit tool for Windows which can be used in batch files or the command prompt to pause the execution and wait for some time.

[11] The command is available as a separate package for Microsoft Windows as part of the UnxUtils collection of native Win32 ports of common GNU Unix-like utilities.

Possible uses for sleep include scheduling tasks and delaying execution to allow a process to start, or waiting until a shared network connection most likely has few users to wget a large file.