---
name: "itimerspec"
section: "3type"
platform: "linux"
package: "man-pages"
version: "6.19-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/itimerspec"
---

# itimerspec(3type)

interval for a timer with nanosecond precision

## NAME

itimerspec - interval for a timer with nanosecond precision

## LIBRARY

Standard C library (*libc*)

## SYNOPSIS

```
#include <time.h>
```

**struct itimerspec {**     **struct timespec  it\_interval;**  /\* Interval for periodic timer \*/     **struct timespec  it\_value;**     /\* Initial expiration \*/ **};**

## DESCRIPTION

Describes the initial expiration of a timer, and its interval, in seconds and nanoseconds.

## STANDARDS

POSIX.1-2024.

## HISTORY

POSIX.1-1996.

## SEE ALSO

[**timerfd\_create**(2)](/timerfd_create/2.md), [**timer\_settime**(2)](/timer_settime/2.md), [**timespec**(3type)](/timespec/3type.md)