# What are some commonly used timing features of
Node.js?

**setTimeout()** schedules execution of a one-time `callback` after `delay` milliseconds.

The `callback` will likely not be invoked in precisely `delay` milliseconds. Node.js makes no guarantees about the exact timing of when callbacks will fire, nor of their ordering. The callback will be called as close as possible to the time specified.

When `delay` is larger than `2147483647` or less than `1`, the `delay` will be set to `1`. Non-integer delays are truncated to an integer.

**setImmediate()** schedules the "immediate" execution of the `callback` after I/O events' callbacks.

When multiple calls to `setImmediate()` are made, the `callback` functions are queued for execution in the order in which they are created. The entire callback queue is processed every event loop iteration. If an immediate timer is queued from inside an executing callback, that timer will not be triggered until the next event loop iteration.

**setInterval()** schedules repeated execution of `callback` every `delay` milliseconds.

When `delay` is larger than `2147483647` or less than `1`, the `delay` will be set to `1`. Non-integer delays are truncated to an integer.

Sources: *Timers | Node.js v19.3.0 Documentation*. (n.d.). [https://nodejs.org/api/timers.html](https://nodejs.org/api/timers.html)